Whilst the histories of this period tend to concentrate on the rise of Rome in the west, we must not forget that at the same time a new empire arose in the east, one that mirrored Rome’s relentless push across the Hellenistic world. Unlike Rome, the Parthians represented a more traditional Hellenistic state, being a feudal empire united by force and ruled over by a dynasty (the Arsacids) that was considered alien to the majority of the peoples they ruled over. Yet the Parthians also represented a new force in history, a warrior race of horsemen from the steppes of central Asia who overran the traditional established kingdoms of the east. The Parthians ruled over an empire that, at its peak, stretched from the borders of India and China in the east to the Euphrates in the west and occasionally beyond.26 Yet, despite the fact that for nearly four hundred years they were one of the two major superpowers of the ancient world, the Parthian civilisation has long been shrouded in obscurity. Even their very name, ‘Parthian’, is a western derivation.27
There are three major reasons for this. Firstly the Parthian empire was a hegemonic one, rather than a unified civilisation in its own right. The Parthian peoples were small in number and lacking in a distinctive culture, in comparison to the other peoples of the Middle East whom they ruled. Secondly, when the Parthian Empire collapsed in the 220s AD, they were replaced by a new dynasty, the Sassanids, who attempted to erase all traces of the Parthians, who they considered to be a non-native race. The third reason is one of chance, as a number of Parthian histories were written by the ancient Greek and Roman authors (a process given life by their victory at Carrhae), but none of them have survived into the modern world (see appendix three).
Therefore, we face a shortage of native documents and narrative histories, from either the east or the west. What we have left are scraps of information in the remaining western sources, archaeological information and numismatics (again see appendix three), though on occasions these can be contradictory, especially in terms of the origins of the Arsacid dynasty. Until they invaded and annexed Mesopotamia in the 140s BC the Parthians had largely escaped the notice of the more advanced civilisations of the east, but from this point onwards, events involving the Parthians became part of the established historical record. The events of the previous century of the Arsacid dynasty of Parthia were also written about from this point onwards, though the chronology of these events is far less certain.
Parthia prior to the foundation of the Arsacid Dynasty
Whilst we have little detail for events in the region of Parthia prior to the 240s BC, we can recreate the broad picture. The region of Parthia lay to the east of the Caspian Sea, crossing what are now the countries of Iran and Turkmenistan. The region was on the edge of the central Asian steppes and was populated by a number of semi-nomadic Scythian tribes. References to the inhabitants of the region can first be found in the historical record when that area was conquered by Cyrus the Great, founder of the First Persian Empire (c.550–330 BC). The exact details of the conquest of this area are not clear, but for the first time the inhabitants of the region came into contact with the wider ancient world and found themselves on the edge of the first great empire of ancient history (stretching from the Indus to Greece). Apparently this new status did not agree with the inhabitants and as early as the 520s BC we find that the region of Parthawa was engaged in a revolt, which was subsequently crushed with a heavy loss of life.28From this point onwards it appears that the Parthians remained loyal subjects of the Persian Empire, being combined with the other races of the region into a satrapy (or province). Persian rule would not have been overly harsh for the Parthians, consisting of little more than a Persian satrap (governor) to administer the area on behalf of the Persian king, though it may have forced them to settle down more as a people, given the Persian demands for tribute and men. Certainly it appears that along with the other races that formed the Persian empire, the Parthians supplied troops to their Persian overlords for the various Persian military expeditions, including the Persian invasion of Greece under Xerxes (480–479 BC).29
Other than these occasional glimpses in the sources and the archaeological remains, we have little trace of the Parthian region in these centuries. They remained a semi-barbarous tribal people on the fringes of a great empire, whose exact nature is impossible to determine. All this was to change with the arrival of the Macedonian king, Alexander the Great, who invaded the Persian empire in 334 BC. Once again we can find traces of Parthian troops fighting in the Persian army at the Battle of Gaugamela 331 BC.30 With the defeat and subsequent death of the Persian ‘Great King’, Darius III, in 330 BC, the Persian empire collapsed and in its place stood the empire of Alexander the Great. Once again Parthia became a vassal state on the northern edges of another great empire, this time a Macedonian one.
With Alexander’s premature death in 323 BC his dreams of a united ancient world empire died too and his territories were divided up between his various generals. These then entered into a generation of bloody dynastic wars which saw the emergence of a new order in the ancient world: the Hellenistic age. As these wars were well documented by the ancient sources, we find a number of traces of the Parthians in the following years. Upon the death of Alexander, his regent Perdiccas placed the satrapy of Parthia under the control of a man named as Phrataphernes.31 In 321 BC, when another of Alexander’s generals was in the ascendant, this time Antipater, Parthia found itself ruled by a Philip.32
By 317 BC the wars had reached Parthia itself. The satrap of Media, a man named Pithon, invaded Parthia and killed its satrap, Philotas (when he had replaced Philip is unknown). Pithon then placed his brother, Eudamus, as ruler of the province, but the other local rulers formed an alliance, invaded Parthia and drove both men from the region.33 Thus Parthia, along with most of the region, found itself a pawn in a much larger game. What effect these invasions and changes of ruler had on the inhabitants of the region we cannot tell. Certainly it appears that Parthia was a useful region for the contestants to possess and later, at the Battle of Paratacene in 317 BC, we find Parthian troops in the army of Antigonus. Diodorus’ account states that
‘On one wing he stationed the mounted archers and lancers from Media and Parthia, a thousand in number, men well trained in the execution of the wheeling movement’.34
This is our first recorded glimpse of the Parthian military, and shows us the reputation that the Parthian cavalry had, even in this early period.
When the initial round of wars ended and the situation had stabilised (after the Battle of Ipsus in 301 BC), the Parthians again found themselves with a new overlord, as part of the newly formed Seleucid empire. This new entity was a loose federation of the races spread across the Middle East, from the Indus to the Aegean, which had been annexed by the Macedonian general, Seleucus. However, there were key differences between the empire of Alexander the Great and that of his successor. Firstly, Seleucus had neither the charisma nor the vision of Alexander, who had wanted to unite both the Greek and native peoples into one new civilisation. This new empire was to be ruled by the Greeks for the Greeks and this translated itself into distant rule from the region of Syria, Greek satraps, and a policy centred on the Mediterranean, rather than the east. Thus the Parthians found themselves at a neglected corner of a foreign empire.
Throughout this period, the tribes living in the region of Parthia occupied a space on the very periphery of the ancient world. They were fierce nomadic horsemen but apparently without any form of central government of their own. Although there are initial similarities between the position of Rome and Parthia (both civilisations being on the periphery of the civilised Graeco-Persian world), they represented two diametrically-opposed civilisations. Furthermore, whilst Rome always looked to the Graeco-Persian cultures, the region of Parthia lay at the juncture of a number of civilisations: the Indian states, the Chinese civilisation and the wild nomadic steppes of Central Asia. All of these would have a role in the shaping of this future world power.
The Foundation of the Arsacid Dynasty in Parthia
We must now consider the events that led up to Parthian independence and the establishment of the Arsacid Dynasty in Parthia, which is one of the most confusing episodes in Parthian history. The struggle centres around two different, but interrelating, processes: the decline of the central Seleucid power and the growth of the regions; and tribal migrations. At the centre of all these events is the semi-mythical figure of Arsaces, the first Parthian king. Although a number of histories were written about this process, none survive intact. We have three surviving ancient accounts of how Parthia achieved independence under Arsaces: a mention by the Roman writer Strabo in his work on world geography; an epitome (précis) of the history of Pompeius Trogus by a later compiler named Justin; and a fragment of a Parthian history by the Romano-Greek writer, Arrian (as reported by three later Byzantine writers, all in different forms).35 By quoting all of these, we will soon realise the problems that we face in unravelling this process.36
In Strabo’s Geography, written in the late first century BC or early first century AD, these three passages are relevant:
But when revolutions were attempted by the countries outside the Taurus, because of the fact that the kings of Syria and Media, who were in possession also of these countries, were busily engaged with others, those who had been entrusted with their government first caused the revolt of Bactria and of all the country near it, I mean Euthydemus and his followers;37 and then Arsaces, a Scythian, with some of the Däae (I mean the Apranians, as they were called, nomads who lived along the Ochus), invaded Parthia and conquered it. Now at the outset Arsaces was weak, being continually at war with those who had been deprived by him of their territory, both he himself and his successors, but later they grew so strong, always taking the neighbouring territory, through successes in warfare, that finally they established themselves as lords of the whole country inside the Euphrates.38
At any rate, some say that Arsaces derives his origin from the Scythians, whereas others say that he was a Bactrian and that when in flight from the enlarged power of Diodotus [the rebel governor of Bactria] and his followers he caused Parthia to revolt. But since I have said much about the Parthian origins in the sixth book of my Historical Sketches and in the second book of my history of events after Polybius [both works now lost], I shall omit discussion of that subject here, lest I may be seen to be repeating what I have already said, though I shall mention this alone, that the Council of the Parthians, according to Poseidonius, consists of two groups, one that of kinsmen [of the king] and the other of wise men and Magi, from both of which groups the kings are appointed.39
In Justin’s Epitome of the Philippic History of Pompeius Trogus, dating to the third century AD, these four passages are most helpful:
The Parthians, in whose hands the empire of the east now is, having divided the world, as it were, with the Romans, were originally exiles from Scythia. This is apparent from their very name; for in the Scythian language exiles are called Parthi.40
Subsequently, when the Macedonians were divided into parties by civil discord, the Parthians, with the other people of Upper Asia, followed Eumenes, and, when he was defeated, went over to Antigonus. After his death they were under the rule of Seleucus Nicator, and then under Antiochus and his successors, from whose great-grandson Seleucus they first revolted, in the First Punic War, when Lucius Manlius Vulso and Marcus Attilius Regulus were consuls [250 BC41]. For their revolt, the dispute between the two brothers, Seleucus and Antiochus, procured them impunity; for while they sought to wrest the throne from one another, they neglected to pursue the revolters.42
At the same period, also, Theodotus, governor of the thousand cities of Bactria, revolted, and assumed the title of king; and all the other people of the east, influenced by his example, fell away from the Macedonians. One Arsaces, a man of uncertain origin, but of undisputed bravery, happened to arise at this time; and he, who was accustomed to live by plunder and depredations, hearing a report that Seleucus was overcome by the Gauls in Asia, and being consequently freed from dread of that prince, invaded Parthia with a band of marauders, overthrewAndragoras his lieutenant, and, after putting him to death, took upon himself the government of the country. Not long after, too, he made himself master of Hyrcania, and thus, invested with authority over two nations, raised a large army, through fear of Seleucus and Theodotus, king of the Bactrians. But being soon relieved of his fears by the death of Theodotus, he made peace and an alliance with his son, who was also named Theodotus; and not long after, engaging with king Seleucus, who came to take vengeance on the revolters, he obtained a victory; and the Parthians observe the day on which it was gained with great solemnity, as the date of the commencement of their liberty.43
Thus Arsaces, having at once acquired and established a kingdom, and having become no less memorable among the Parthians than Cyrus among the Persians, Alexander among the Macedonians, or Romulus among the Romans, died at a mature old age; and the Parthians paid this honour to his memory, that they called all their kings thenceforward by the name of Arsaces44
The following three extracts preserve parts of Arrian’s Parthica, written in the second century AD. The earliest of these is Zosimus’ History from the fourth or fifth century AD.
For after the death of Alexander the son of Philip, and of his successors in the empire of the Macedonians, at the period when those provinces were under the authority of Antiochus, Arsaces a Parthian, being exasperated at an injury done to his brother Tiridates, made war upon the satrap of Antiochus, and caused the Parthians to drive away the Macedonians, and form a government of their own.45
The next, Synkellos’ Chronology dates to the eighth century AD.
During the reign of this Antiochos, the Persians [Parthians], who were tributaries to them from the time of Alexander the founder, revolted from Macedonian and Antiochid rule. The reason was as follows:
A certain Arsaces and Tiridates, brothers tracing their lineage from Artaxerxes king of the Persians [465–424 BC], were satraps of the Bactrians at the time of Agathocles, the Macedonian satrap of Parthia. According to Arrian, this Agathocles fell in love with Tiridates, one of the brothers, and was eagerly laying a snare for the young man. But failing utterly, was killed by him and his brother Arsaces. Arsaces then became king of the Persians [Parthians], after whom the kings of the Persians [Parthians] were known as Arsacidae. He reigned for two yearsand was killed by his brother Tiridates, who succeeded him, to rule for thirty seven years. 46
The final version is in the Bibliotheca of Photius, writing as late as the ninth century:
In the Parthica he [Arrian] gives an account of the wars between Parthia and Rome during the reign of Trajan. He considers the Parthians to have been a Scythian race, which had long been under the yoke of Macedonia, the Persians having been subdued at the same time, and revolted for the following reason.
‘Arsaces and Tiridates were two brothers, descendants of Arsaces, the son of Phriapetes. These two brothers, with five accomplices, slew Pherecles, who had been appointed satrap of Parthia by Antiochus Theos (the Seleucid monarch), to avenge an insult offered to one of them; they drove out the Macedonians, set up a government of their own, and became so powerful that they were a match for the Romans in war, and sometimes even were victorious over them’.47
Furthermore, we have four later Graeco-Roman sources which comment on the Parthian origins. The first, Quintus Curtius Rufus, from the first century AD, backs the barbarian invasion version of events:
the entire column was brought up by the Parthyaei, a race living in the areas which are today populated by Parthians who emigrated from Scythia.48
But the other three, from the second and third centuries AD, back the native revolt theory. We have Appian’s account from the second century AD:
He [Ptolemy] invaded Syria and advanced as far as Babylon. The Parthians now began their revolt, taking advantage of the confusion in the house of the Seleucidae.49
Dio Cassius’ History of Rome written in the third century AD:
when the successors of Alexander had quarrelled with one another, cutting off separate portions (of his empire) for themselves and setting up individual monarchies, the Parthians then first attained prominence under a certain Arsaces, from whom the succeeding rulers received their title Arsacidae.50
And finally, Herodian’s History of Rome, also from the third century AD:
When these governors quarrelled and the power of the Macedonians was weakened by continual wars, they say that Arsaces the Parthian was the first to persuade the barbarians in those regions to revolt from the Macedonians. Invested with the crown by the willing Parthians and the neighbouring barbarians, Arsaces ruled as king.51
Thus we can now see the problem with which we are faced. There are two clear strands of thought, which sometimes overlap. One is that Arsaces was the leader of a tribe of Scythian barbarians which invaded and overran the region of Parthia, and the other is that there was a native revolt led by Arsaces who freed Parthia from Seleucid influence. Thus we have full-blown invasion and tribal migration (though Justin downgrades this to a small band of marauders) versus a native revolt led from within. Of the latter, the sources quoted above cannot make their minds up whether Arsaces was Parthian or Bactrian.
In connection with this problem, we have a number of further pieces of information. Firstly, we know that the Parthians had a dating system based on the accession of Arsaces to the throne and that it equates to the year 248/247 BC.52 Secondly, we know that the neighbouring Seleucid province of Bactria revolted under its governor (as mentioned above, either a Diodotus or a Theodotus) and achieved full independence as the kingdom of Bactria. Added to this is the general collapse of the Seleucid empire in the 240s/230s period. The Third Syrian War (c. 246–241 BC), between the Seleucids and the Egyptians, saw heavy Seleucid losses and a collapse of Seleucid authority. This was followed by a fraternal civil war (c. 240–236 BC) which saw the Seleucid empire decline even further. Thus the decade from 246 to 236 BC was the perfect time for either a revolt or an invasion, with the Seleucids in no position to offer any resistance in the region.
A number of scholars have attempted to construct a narrative that ties all the elements together and attempts to make sense of them.53 With due respect to them, the existing evidence makes that impossible to do without making great leaps of logic that are not supported by the remaining evidence. Lerner, however, does make one important point, namely that the dating of the founding of the Arsacid era (c. 248/247 BC) does not have to correspond to Arsaces’ conquest of Parthia (which would place it before Seleucid power started to decline, directly contradicting both Strabo and Justin).54 The date could relate to when Arsaces was crowned king (or ruler) of his tribe (either the Aprani or the Däae). We know that the Seleucids had been having problems with the Scythian tribes of the Caspian region, as it is recorded that the Seleucid general, Demodamus, was sent to the region c. 280 BC to suppress them.55
With this date issue opened up, we can now look at the two main elements that form the foundation tale, namely that Arsaces was both Scythian and was connected with Bactria. The first thing to note is that none of the sources speak of a full-scale barbarian migration to the area. Strabo states that Arsaces invaded with ‘some’ or ‘certain’ (TInAZ) of the Däae, rather than many, and Justin tells us that he had a band of marauders. Thus we can conclude that this was not a full-blown barbarian migration, but was merely that Arsaces invaded Parthia, killed the governor, declared himself king and then led Parthia to independence. What are we to make of his Bactrian connection then? Attempts have already been made to connect the two elements of him being Scythian in origin and the Bactrian connection, by stating that his band/tribe attacked Bactria first and then were repulsed, but again there is nothing to back this up in the sources.56 Given that we know that the governor of Bactria revolted, we can ask ourselves whether during this revolt he used Scythian tribesmen as mercenaries, and if he did so then might they be Arsaces and his warband? At the conclusion of the campaign to free Bactria from Seleucid rule, we can then suggest that Diodotus (the former governor of Bactria, now king) fell out with his mercenaries, as invariably happened, and they then invaded the neighbouring Seleucid province of Parthia and took over.
In this way we can construct a more logical sequence of events, which does not require a tight chronology. In 248/247 BC a man named Arsaces became the warchief of his band/tribe of Scythian barbarians, who occupied the lands bordering the Seleucid empire in the region of the Caspian Sea (in what is now modern Turkmenistan). During the period c. 246–236 BC, three major events occurred in the region which transformed Arsaces from tribal chief to king of an independent country. Firstly, Seleucid authority in the east crumbled due to a series of wars and setbacks in the west, allowing the governor of Bactria to declare independence. Secondly, this governor used Arsaces and his warband in his war of independence, but the two parties fell out at some point. Thirdly, Arsaces and his warband, which included his brother Tiridates, then invaded Parthia, killed the Seleucid governor and established themselves as the new ruling elite of the semi-nomadic province. Once they had established control, Arsaces then made himself king and declared Parthia to be independent. We even have a fragment of an ancient source that tells us where this event actually happened: ‘the City of Asaac in which Arsaces was first proclaimed king; and an everlasting flame is guarded there’.57
Thus we have a chain of events that includes both traditions of Arsaces being Scythian, yet coming from Bactria. This only leaves us the Arrian-inspired events that include the Parthian governor and a homosexual angle. It is again possible that when Arsaces was driven out of Bactria he did not necessarily launch an immediate attack on Parthia, but could have offered his warband’s services to the Parthian governor, against Diodotus of Bactria, with whom he had fallen out. It is then entirely possible that Arsaces promptly fell out with the Parthian governor (perhaps over his brother) and, rather than flee another province and finding Parthia far weaker than Bactria, slew the governor. He then established himself and his men as the new rulers of the Seleucid province of Parthia and declared independence, with himself as king. Thus we have a sequence of events that includes the main themes of each of the surviving sources without stretching the evidence too far or getting tied up with an exact time-frame. We can see that the foundation of the Arsacid dynasty in Parthia came about as a result of the temporary collapse of Seleucid rule in the east, which led to the revolt of Bactria and the Arsacid takeover in Parthia.
Therefore, the former Seleucid province of Parthia gained a new ruling elite; a Scythian warband, which seems to have been quickly accepted by the semi-nomadic peoples of the province, especially given a long rule of foreign (Persian and then Greek) governors. The fragments of Arrian all seem to contain traces of the Arsacids claiming descent from the first Persian rulers (the Achaemenids), which was probably done to help justify their rule.58 It appears that the first capital of an independent kingdom of Parthia was the city of Nisa, which lies just east of the present city of Ashgabat (the capital of modern Turkmenistan), though the Parthian capital moved west as their empire grew.59
With this new ruling elite in place, the province was transformed into a state in its own right, but one that was still little more than an independent semi-nomadic region, which at the time appeared to possess few factors that would lead to the foundation of a new world power. If anything, it was neighbouring Bactria, with its numerous cities and control of the eastern trade routes, that looked more likely to become the dominant power in the region. Although Arsaces appeared to have established Arsacid rule firmly within Parthia, he still faced two massive external threats. Not only did he have a dominant Bactria on his eastern flank, but he had the Seleucid empire to his west, which, when it recovered from its internal difficulties, would be eager to regain its lost territories.
The Struggle for Independence (c. 240s–176 BC)
Before we examine the drawn out Parthian struggle to remain independent, we must first deal with the problem concerning the length of Arsaces’ reign. Here we have two totally contradictory sources. The first is Synkellos:
He reigned for two years and was killed by his brother Tiridates, who succeeded him, to rule for thirty-seven years. 60
and the second is Justin:
Thus Arsaces, having at once acquired and established a kingdom, and having become no less memorable among the Parthians than Cyrus among the Persians, Alexander among the Macedonians, or Romulus among the Romans, died at a mature old age61
We have two differing traditions at play here. One has Arsaces ruling for a long reign, being succeeded by his son, who in turn is replaced by a grandson of Tiridates, named as Priapatius (who ruled as Arsaces III). The second tradition has Arsaces being murdered by his own brother (the very one that he had saved from the clutches of the Parthian governor) within just two years, who then goes onto rule for a long reign until he is succeeded by his grandson Priapatius. So which are we to believe?
It is suspicious that none of the earlier sources mention this fate of Arsaces, and that it mirrors the origins of Rome (with Romulus killing his brother Remus). Furthermore as one modern author puts it
the importance of Arsaces I is far greater in the later imagination of the Arsacid Empire . . . Why would the Parthians recall a leader who had held power for not two or three years, and never in fact ruled in Parthia proper at all, on every coin they ever issued, and in the name of every king they ever had62
Therefore, the most obvious way to proceed is by accepting that Arsaces did indeed rule for a long period, down to c. 211 BC in fact, and was the man who did so much to free Parthia from Seleucid domination and build it up into a strong regional power. Having dealt with this issue, we can now turn our attention to the rest of Arsaces’ reign. It appears that both he and his men did not dwell upon their new status long, as we are told that the Parthians (as we can now call them) soon invaded the neighbouring Seleucid province of Hyrcania and annexed it,thus increasing the size of Parthian territory and Arsaces’ power-base.63 By c. 236 BC, the Seleucid king, Seleucus II, had settled his empire sufficiently to allow himself to mount a campaign to recapture the provinces of Hyrcania, Parthia and Bactria. Once again the details of the period are sketchy, but it appears that he targeted Parthia first and allied with Diodotus of Bactria in an anti-Parthian pact. This was followed by a full- scale invasion of Parthia and the total defeat of Arsaces, who was forced to flee the country altogether and find shelter with the nomadic tribes of the Caspian steppes.64 At this point it appeared as though the Parthian rebellion had been crushed and Parthia would be once again relegated to a footnote of history.
Instead, Arsaces managed to engineer a remarkable turnaround. Fortunately for him, it appears that Diodotus of Bactria soon died, leaving his throne to his son. Diodotus II soon realised the danger from a resurgent Seleucid empire; it was clear that once Parthia had fallen Bactria would be next. It appears that he therefore reversed the policy of his father and allied with Arsaces, preferring an independent Parthia as a buffer state between Bactria and the Seleucids. With Diodotus’ backing, Arsaces managed to raise a fresh army and challenge Seleucus once more. Justin presents us with the following:
within a short time, Arsaces joined battle with king Seleucus who had come to punish those who had seceded and he [Arsaces] remained the victor. Ever since, the Parthians celebrate this day with solemnity which they have fixed as the beginning of their freedom.65
Arsaces’ defeat of the army of Seleucus finally established Parthian independence. It appears that this victory was made the more complete by the capture of Seleucus himself, who remained a Parthian hostage for some time.66 He was eventually released, but the terms must have been the recognition of Parthian independence.67 With independence secured, Arsaces then established the foundations for a strong Parthia:
while Arsaces, having put the Parthian kingdom in order, assembled an army, laid the foundations of a fortress, strengthened cities, and founded on Mt. Apaortenon the city of Dara, the location of which is such that there is no other city of a more fortified character and more fascinating.68
During this period, Parthia was at peace with Bactria and had a de facto peace with the Seleucid empire.69 However, in 223 BC the Seleucids gained a new and powerful king in the person of Antiochus III, also known as the Great, who did much to restore the Seleucid empire to its former glory. The death of Arsaces (c. 211/ 210 BC) and the accession of his son, Arsaces II,70 along with the breakdown of Parthian-Bactrian relations, presented Antiochus with a golden opportunity to recover the eastern provinces.71
In 209 BC, Antiochus invaded Parthia with a huge army, quoted in one ancient source as being 120,000 strong, though we must question such an extravagant figure.72The new Parthian king, Arsaces II, retreated ahead of the Seleucid forces, destroying the infrastructure as he went. Nevertheless, his forces were defeated at Mount Labus and he could not stop Antiochus invading Hyrcania, where the new Parthian capital of Hecatompylus lay.73 The details of the rest of the campaign have been lost, but the war ended with Parthia’s defeat and a peace treaty which established a compromise situation. The Arsacid dynasty were recognised as rulers of Parthia, but Parthia itself was reduced to being a federal dominion of the Seleucid empire, without being a formal province. Whilst we have no exact details of the nature of this status, it is clear that Parthia was reduced to being a federated ally of the Seleucid empire.74 Thus the many gains of Arsaces I had been overturned and, although the Arsacids remained in control of Parthia, the country had lost both its independence and its fledgling empire.
We know nothing else of the reign of Arsaces II and it is probable that he kept a deliberately low profile following his defeat. We know that he was succeeded on the throne by Priapatius, who designated himself as Arsaces III. This was the first time this appellation had been taken by a member of the family whose real name was not Arsaces. According to Justin this took place c.191 BC, but it has recently been argued that Priapatius seized the throne from Arsaces II and established the rule of the junior branch of the Arsacid family, which descended from Arsaces’ brother Tiridates.75
Though the coup remains speculation it does appear that from this point onward, although they all claimed descent from Arsaces, all subsequent Parthian kings were descended from Tiridates, which may explain the growth of the variant tradition that Arsaces I died quite soon after leading the Parthians to independence and that Parthian power was laid by Tiridates instead.
This defeat and diminution of status was a major setback in the history of Parthia and we know nothing of the internal events that took place for the rest of Priapatius’ reign. The rise of Parthia to superpower status might have ended there if it were not for the help they received from an unusual and unknowing source. As we have seen, with the east secure, Antiochus III turned his attention to the west and mainland Greece, then under Roman protection. A disastrous war with the Romans resulted in the destruction of Seleucid power in the west and shook his whole empire. This defeat appears to have had no immediate effect on Parthia. In c.176 BC Priapatius was succeeded by his son, Phraates (who ruled as Arsaces IV), and it is only from this date that we see the Parthian fightback.
It is difficult to gauge the status of Parthia during the years c. 208–176 BC, given the lack of surviving source material. We can certainly assume that following their defeat and Priapatius’ accession to the throne (whether by coup or not) the Parthians kept a deliberately low profile in fear of angering Antiochus III. We do not know for certain that the Seleucids left a garrison in Parthia, but given the trouble that they had caused the empire, we can assume that it was the case. We can also assume that Antiochus’ war and defeat against the Romans would have seen that garrison removed and thus allowed the Parthians to rebuild their own forces and re-establish her independence from Seleucid interference. Following the peace terms imposed on them by Rome, the Seleucids were unlikely to be able to stage a campaign on the scale of Antiochus’ invasion of 209 BC, virtually guaranteeing Parthia’s independence from them.
Thus the actions of Rome on one side of the ancient world saw important repercussions on the other, revealing the delicate balance of the ancient world order. Once again we can see that Rome’s interference with the established Hellenistic order was allowing new states to emerge that would ultimately threaten Roman security, a result of Rome’s haphazard policy with regard to the east.
The Rise of a New Power (176–138 BC)
With Rome’s humbling of the Seleucid empire, the way was open for Parthian expansion to the west. It is the next two monarchs, Phraates I (c.176–171 B.C) and Mithradates I (c.171–138 B.C), that led the Parthians on the road to imperial status. Although he only reigned for five years, Phraates disregarded over thirty years of Parthian stagnation and launched aggressive wars against his immediate neighbours, both to the west and south, subduing the tribes that lived there. Upon his death, this expansionism was taken up by his younger brother, Mithradates I (no relation to the monarchs of Pontus). At the same time as Mithradates’ accession, the king of Bactria was overthrown by a usurper, plunging Bactria into chaos. Mithradates took this opportunity to invade Bactria (Parthia’s closest rival in the region) and annexed the bordering territories of Tapuria and Traxiana, though we are unsure of the exact date of this campaign (most likely during the early 160s BC).
A potential threat to Parthia from the new Seleucid king, Antiochus IV, was averted in 163 BC, when he was murdered whilst campaigning in the east of the empire. With Bactria cut down to size and the death of the Seleucid king, Mithradates again showed his strategic abilities by launching an invasion of the Seleucid-controlled region of Media (a major regional power in its own right) in the 150s BC (though again this is hard to date exactly). After a long and protracted war, whose exact details are lost to us, by 148 BC Media had been conquered. Rather than ruling it directly, Mithradates appointed a governor to rule the province in his name, thus creating the first proper imperial province of the Parthian empire. This was not the only way in which the Parthian empire was taking shape, as this conquest had brought Parthian territory to the river Tigris itself, beyond which lay Mesopotamia, the cradle of all great eastern empires, containing the great cities of Babylon and Seleucia.
Building upon his already-great success, Mithradates determined to continue and launched his most ambitious campaign yet. In 141 BC he invaded Mesopotamia, thus reversing two hundred years of conquest from the west. Defeating a general of the Seleucid king, Demetrius II, Mithradates accepted the surrender of the strategic cities of Seleucia and Babylon and had himself re-crowned as ‘King of Kings’ in Seleucia.76 However, Mithradates had to break off the campaign to return to Parthia proper; for what reason we do not know, though border raids by barbarians are suspected. Nevertheless, the Parthian army had developed in such a way that he was able to leave a force to complete the conquest of Mesopotamia, under an unknown general, whilst he himself campaigned on Parthia’s eastern borders, perhaps to repel raiders from China.
In his absence, the Seleucid king attempted to re-capture Mesopotamia but was defeated in battle by Mithradates’ general (in 139 BC). The king himself was captured and transported back to Parthia, where he lived as an honoured captive and was even married off to one of Mithradates’ daughters. Mithradates returned to the west in person and added the minor kingdom of the Elymaeans to the Parthian empire, as well as the old Persian capital city of Susa. In addition to this territory, the Parthians took a considerable amount of loot with them back to Parthia, taken from the Greek cities and temples of the region.
Having achieved these great conquests, in the winter of 138/137 BC Mithradates died peacefully, being justifiably labelled as the true founder of the Parthian empire. On his accession, Parthia was a small regional power just recovering from forty years of Seleucid domination. On his death, thirty-three years later, the Parthian empire was the unquestioned dominant power in the region. Bactria had been humbled, Media and Mesopotamia had been conquered and the Seleucid empire driven back west of the Euphrates. The reigning Seleucid king had been made a captive and a subservient son-in-law. For the first time in two hundred years, the great cities of Susa, Babylon and the whole Mesopotamian region were free from Greek rule. In historical terms the tide had turned and the Greek advance eastwards had now turned into a retreat back towards the Mediterranean.
During these years, the Parthian army had developed into a devastating fighting machine, defeating armies from both the east and the west. Although its exact nature is unknown, we can surmise that it was in this period that the Parthians perfected their legendary cataphract cavalrymen to complement their mounted archers. Certainly by 138 BC, just as Rome was the dominant power in the Mediterranean, Parthia was dominant power in the east, and designated heirs to the first great Persian Empire. An attack on the remnants of the Seleucid empire and a push for the Mediterranean seemed inevitable, especially given the presence of a captive Seleucid monarch who could act as a puppet ruler.
Unlike the rise of the Roman empire in the west, however, the Parthian empire had one crucial difference; as with all eastern empires, they were reliant upon the brilliance of the individual monarch. Arsaces had established a strong independent Parthia, but his successors had overseen its decline. Mithradates had overseen Parthia’s rise to being the region’s superpower, but could his successors hold onto it?
The only possible way out of this dilemma was to create a command structure that would allow competent generals to develop and as the Parthians’ Mesopotamian campaign had shown, there were certainly encouraging signs in this direction; the crucial victory over the Seleucid forces had been won by one of Mithradates’ generals (whose identity is lost to us). Furthermore, the Babylonian chronicles record that the Parthian king appointed five generals to command the Parthian forces in the region. From their names, Antiochus, Nikanor, Hyspaosines, Philinos77 and Enius78, it appears that generals of Greek or local origin were employed there rather than using Parthian generals.
This policy had both benefits and drawbacks. The benefit being that they had local knowledge and could rule the area in Parthia’s name without looking like foreign oppressors. Furthermore, they would not be a threat to the Parthian throne, as a powerful Parthian general would be. The drawback was that their loyalty could be in question, as happened when the general Antiochus betrayed the Parthians to a local regional power, Elam.79 However, we know little of the Parthian military command structure or how much the king relied upon non-Arsacid generals overall.
By contrast, the Romans in this period did not suffer from this weakness. The nature of the republican system and the ruling oligarchy provided Rome with a multitude of able commanders (along with the inevitable poorer ones). This is one of the key factors that allowed for the seeming relentless progress of the conquests of the Republic. When the Romans eventually abandoned their republic in favour of an empire then they too succumbed to this ‘dilemma of command’.
Collapse and Recovery (138–88 BC)
In the case of Parthia, Mithradates’ son, Phraates II, came to the throne in 138 BC, but the decade of the 130s saw little in the way of preparations for a campaign against the remnants of the Seleucid empire. It appears that the whole Seleucid issue had been allowed to deteriorate. Despite his luxurious treatment, the captured Seleucid king, Demetrius, attempted to escape captivity and reach his homeland on two separate occasions, both of which ended in his capture and subsequent pardon. Furthermore, the situation in the Seleucid empire itself had stabilised. Defeat and the loss of Mesopotamia and the king had led to a usurper, Tryphon, seizing the throne, which sparked off yet another Seleucid civil war. Yet the Parthians failed to capitalise on this opportunity, perhaps waiting for the situation to deteriorate even further. Instead, however, a ‘legitimate’ Seleucid claimant seized the throne and unified the empire under his leadership. This was Antiochus VII, who was perhaps the last great leader the Seleucids produced. With the throne secure, he immediately turned his attention to recovering Mesopotamia, if not the rest of the eastern lands.
This failure to capitalise on Mithradates’ conquests could be used as evidence for the weaknesses of the Parthian (and Seleucid) systems, namely their reliance on kings with dynamism. In their defence, it was possible that the Parthians were distracted by the migratory activities of the tribes on their Chinese border, who we know to have been active in this period. In any case, the Parthians certainly neglected events in the west and paid the price for it. In 130 BC, Antiochus VII invaded Mesopotamia with an army of over 80,000 men (the largest for a generation).80 Again we possess little exact detail for the subsequent war, but what is clear is that it was a disaster for the Parthians, who were defeated in three separate battles. We only know the location of one of them, on the River Lycus, where the Parthian general Indates was defeated.81
These defeats were followed by the revolt of the city of Seleucia and the murder of its Parthian governor, Enius, with the city of Susa soon following.82 Clearly this showed the tenuous nature of the Parthian conquest of what had been Greek territory for two hundred years (again another factor to bear in mind for the later Roman campaign).
By the end of the year, Parthia had not only lost Mesopotamia, but also the military reputation that Mithradates had taken three decades to establish. As a consequence, Antiochus advanced into Parthian-held Media, gaining allies from all the tributary races and cities that had previously sworn allegiance to the Parthians. In a move that showed that he was clearly not in the same mould as his father, Phraates attempted to negotiate, although it is possible that he was buying time. Antiochus’ terms were the destruction of the Parthian empire through the return of all of its conquered territories, outside of Parthia proper, to the Seleucid Empire.
Finding the terms totally unacceptable and being unable to defeat Antiochus in open battle, Phraates resorted to underhand tactics. Firstly, he released Demetrius and sent him back to Syria, something that would undermine Antiochus VII; secondly, he set about undermining Antiochus’ military position in Media. Antiochus had ended the campaign of 130 BC by wintering in Media rather than withdrawing back to Mesopotamia. Thus the burden of feeding and housing such a large army fell on the native populations of the region, who naturally resented this treatment at the hands of the Greeks. This resentment was fanned by Parthian agents into full scale revolt.
In the spring of 129 BC in a superb piece of planning, the cities of Media rose up and attacked the scattered, resting army of Antiochus, just as Phraates took to the field himself and advanced into Media. Despite being advised to retreat, Antiochus offered battle, which, given the disorganised nature of his army, was only ever going to have one outcome. The Seleucid army was destroyed, along with Antiochus and his dreams of the restoration of the Seleucid empire. Phraates had succeeded through a use of cunning and brute force, where brute force alone had failed. Phraates advanced into Mesopotamia, which was easily re-conquered. Having turned defeat into victory, Phraates prepared for an invasion of Syria, now controlled by Demetrius once more. Victory would have put the Parthians on the Mediterranean coast of the Middle East, some sixty years before the Romans annexed it. Unfortunately for the Parthians however, imminent victory in the west was undermined by a new perilous threat from the east.
For a decade or more, the lands bordering Parthia’s eastern border had seen the advance warnings of a full-scale barbarian migration, as periodically occurred all over the ancient world. This is perhaps what had caused Mithradates to return eastwards in the 130s BC and what had delayed Phraates in his campaign against the Seleucids. Pressures in the northern steppes had led to a fierce nomadic tribe known as the Saka moving into the region adjoining the Parthian border, from where they mounted raids across the border. Phraates had clearly tried to solve this problem earlier by a policy of co-option, as the sources indicate that a large number of Saka tribesmen had been hired to fight for Parthia in the war against Antiochus. However, they were still making their way westwards towards Media when Antiochus’ army was destroyed. Unwilling to demobilise empty handed, they then turned on the Parthians and ravaged the territories of the empire, penetrating as far west as Mesopotamia.83
Phraates’ policy of co-option had allowed a dangerous barbarian enemy into the heart of the empire. It was a lesson that he was slow to learn. In the short term, the Parthians’ problem with the Saka became considerably worse, when it turned out that the tribesmen who were now raiding their territory were merely the advance guard, with the whole tribe approaching Parthia’s northeastern border. Between the Parthians and the Saka lay the kingdom of Bactria, which proved to be no match and was devastated.
Abandoning the invasion of Syria, Phraates made for the eastern border, but not before making an ill-advised and ultimately fatal error. Believing that he would need a large force to defeat the Saka, he conscripted a large number of the Greek soldiers from Antiochus VII’s defeated army. He chose to ignore the fact that the Greek cities had recently revolted and that the Saka mercenaries were still ravaging his territory. With an army containing a large number of Greeks soldiers whom he had just defeated, Phraates returned to the east to engage the Saka in battle.
In 128 BC, in an unrecorded location on Parthia’s eastern border, the Parthian army met the Saka barbarians in battle. During the battle the inevitable occurred when the Greek soldiers deserted the Parthians, allowing them to be routed and slaughtered. Phraates himself perished in the fighting, making him the first Parthian king to die in battle. Parthia now found herself fighting for her existence in the face of a barbarian onslaught and the situation soon got worse. The new king, Artabanus I (the uncle of Phraates) resorted to buying the Saka off, which appears to have worked in the short term. However, a second wave of migrating barbarians followed the Saka, named in the sources as the Tochari, and Artabanus met them in battle in the region of Bactria in 124 BC. He too was killed in battle (at the point of a poisoned arrow) and another Parthian army met defeat (the fifth in a decade).84
When Mithradates II succeeded to the throne in 124 BC, he faced an empire in crisis. Not only were the eastern borders, nearest to the Parthian homeland, being overrun by barbarians (who had killed the last two kings in battle), but the province of Mesopotamia was undergoing serious problems of its own. The governor installed by Phraates II in 129 BC, Himerus (or Euhemerus), had engaged in a policy of retaliation against the Greek inhabitants for their revolt the previous year, thus provoking them to the point of open insurrection once more.85 Furthermore, a new kingdom had been created on the mouth of the Tigris (where it emptied into the Persian Gulf). During the several conquests of Mesopotamia in the preceding decade, the minor city of Antiochia had found itself ignored by both warring sides, due to its southern position. The Seleucid governor, Hyspaosines, seized the opportunity and declared independence, changing the city’s name to Spasinou Charax (the city of Hyspaosines) and making it the capital city of the new kingdom of Characene. Taking advantage of the Parthian weakness, he then invaded Mesopotamia proper and by 127 BC had conquered both Babylon and Seleucia.86
Thus Mithradates II faced problems in both the east and the west of the Parthian empire. For the next thirty years he worked tirelessly as ruler of Parthia and re-established the empire as a major power. The exact details of his campaigning have been lost to us, but it appears that the barbarians in the east had eased up on their westward push, settling in the Afghan regions of Helmand-Quandahar and the Punjab in India. This allowed Mithradates to deal with the western problems first. In 122 BC he re-invaded Mesopotamia and attacked the kingdom of Characene. Within the year the Parthians had re-occupied both Babylon and Seleucia and had soundly defeated Characene, which now became a vassal state of the Parthian Empire.
With the west secured, Mithradates turned his attention back to the east. Again our sources provide us with little detail, but it is clear that he fought a number of campaigns against the barbarian tribes on, or within, the borders of the Parthian empire. We have no dates, but Chinese sources appear to indicate that the Parthians had secured the border city of Merv by 115 BC. Other sources state that he defeated the barbarians on a number of occasions and added a number of Bactrian cities to the his empire.87
It is clear that by c.100 BC the eastern border of the empire was secure enough to allow the trade routes with the Han empire of China to flourish (leading to the establishment of the great Silk Road). Chinese records show that the Han dynasty sent an embassy to the court of Mithradates sometime in the period 120–90 BC to formalise trade relations, showing both the stability and the powerful role of the Parthian empire (see appendix III). It is clear that Mithradates II had ended the barbarian threat which had threatened the very existence of the empire, for which he was given the title ‘The Great’.
These threats dealt with, Mithradates began a fresh period of expansion in the west, attacking and defeating the newly emerging kingdom of Armenia. He did not occupy the territory, but he did take hostage the heir to the Armenian throne, Tigranes (who, as we have seen, later went to war with the Romans), to ensure future Armenian good behaviour. When the old king died in 94 BC, Tigranes was installed on the throne of Armenia with the aid of Parthian forces, in return for which the Parthians received seventy valleys worth of territory.88
Thus, by the late 90s Mithradates II had not only stabilised the Parthian Empire but had once again established it as the superpower of the region. His eastern borders were secure and had established firm relations with the Han empire of China. To the west, Mesopotamia was firmly under Parthian control and no further threats were posed by either Seleucids or Characenes, while Armenia was now a subservient ally. Parthian policy appeared to have changed from one of outright annexation to one of suzerainty over its neighbours.
The focus of Parthian rule had moved westwards with the seat of government moving from Parthia proper into Mesopotamia and a new winter capital city of Ctesiphon, on the Euphrates (the summer capital being Ectabana in Media). The reasons for this are unclear, but, as the Saka invasion had shown, the old Parthian capitals of Nisa and Hecatompylos were vulnerable to barbarian incursions from the northern and eastern steppes. The province of Mesopotamia was now firmly in Parthian hands and provided a western outlook to the empire, and the monarchy inherited a more Hellenistic nature. Having a capital city in Mesopotamia also provided a powerful political and cultural statement (in many ways mirroring Peter the Great’s decision to move the Russian capital from Moscow to St Petersburg in the 1700s). In addition, with all the great eastern empires having centred their civilisations on that region, the Parthians could claim to be the natural heirs to the Persian empire, rather than the failing, and alien, Hellenistic states.
It was also in Mithradates’ reign that the Parthians took their first step in relations with the wider western world, in the form of the first contact between Parthia and Rome. Whilst both empires would have been aware of the other, neither would have considered the other a serious threat prior to the 90s BC (though had Parthia invaded Syria then this would have undoubtedly changed). As we have seen, by the 90s BC Rome had realised that their neglect of the east had allowed new states to rise from the ashes of the Seleucid empire, in particular Mithridates VI of Pontus. By 92 BC, Rome had become so alarmed by the rise of Mithridates VI that the Senate commissioned the governor of Cilicia, Lucius Cornelius Sulla, to intervene in the Asia Minor region and restore the independence of the kingdom of Cappadocia (which had been annexed by Mithridates VI). Whilst for Rome, the immediate threat was the kingdom of Pontus, they would have been well aware of the advance of the Parthian empire. Armenia had recently been defeated in battle and was now under Parthian influence. As detailed in chapter one, the Romans were never slow in spotting, or even inventing, new dangers to their much sought after security.
The details of how the Romans and Parthians arranged their first meeting are unknown, but what is known is that Sulla met with a Parthian ambassador, Orobazus, by the Euphrates. Whilst the details of the meeting are obscure, it does appear that there was a sharp cultural difference between the two sides (inevitable given one was an oligarchic republic and the other an oriental monarchy). It does not appear that either participant had the authorisation to conclude a treaty, so the meeting took the form of a mutual exchange of goodwill. Orobazus appears to have been treated in high-handed fashion by Sulla, a fact which cost the former his life upon his return to the Parthian court.89
Whatever the result, it is highly doubtful that the Parthians and Romans agreed on a line of demarcation between the two empires, as this would have run against both sides’ aims and interests in the region. In any event, soon after this meeting, Tigranes of Armenia, a client of Parthia, conducted an agreement with Mithridates VI of Pontus, placing the Parthians, if not on Pontus’ side, then nearer them than the Romans. Events in 88–87 BC did little to calm Roman fears, as the Parthians expanded this policy of suzerainty over the remnants of the Seleucid empire, which was once again in the midst of another civil war. It appears that the Parthians intervened on the side of one contender, Philip, against the reigning king, Demetrius III. Demetrius was defeated and captured by Parthian forces and, like his namesake, was sent into comfortable exile in Parthia proper at the court of Mithradates II.90An intervention of this sort placed the Seleucid empire (what was left of it) firmly in the orbit of Parthia, whereas it had traditionally fallen to Rome to interfere in Seleucid affairs in this way. It had shown how far the balance had tipped between Seleucia and Parthia and how far Roman influence had waned in the region, especially given the invasion of the Roman empire by Mithridates VI in 88 BC and Rome’s own subsequent descent into civil war.
Thus the reign of Mithradates II, shows us both the strengths and weaknesses of the Parthian empire. When controlled by a monarch of ability and determination, the Parthians proved to possess a formidable military machine, capable of defeating any of their neighbours. This military success was accompanied by a shrewd policy of economic and diplomatic links with the states on her borders. By the end of Mithradates’ reign (87 BC), the Parthian empire was the unchallenged master of the Middle East, with a firm hold on Mesopotamia demonstrated by the establishment of a new capital on the Euphrates. The states not directly under her control, such as Armenia and the Seleucid empire had been humbled and brought under Parthian influence. In the east, her borders were secure and trade was flourishing with China, benefiting the Parthian economy immensely. The barbarians had been defeated and old rivals such as Bactria had fallen.
But was this due to the strength of the Parthian system or the brilliance of one man? The answer is of course an element of both, but Parthia’s history had shown that in the hands of an able monarch they were capable of massive expansion, as with Arsaces I and Mithradates I. Yet both these periods had been followed by periods of massive decline, as less-talented monarchs proved unable to build upon these achievements. Was this again to prove the case in the aftermath of Mithradates II?
The Eclipse of Parthia (87–58 BC)
It is difficult to say who exactly was ruling the Parthian empire in this period, as for the years from 87–70 BC we appear to have three kings; Gotarzes I, Orodes I and Sinatruces I. All three appear to have overlapping reigns, including Gotarzes who first appears with the title ‘King of Kings’ circa 91 BC. Whilst there are no records of a civil war in these years, it is clear that the Arsacids in particular and their empire in general entered a period of confusion and uncertainty, which some scholars refer to as a Parthian ‘Dark Age’. It is likely that Gotarzes and Orodes were in conflict with each other. By 76 BC, however, we hear of a Sinatruces being offered the throne, a man who was 80 years old at the time. It appears that he was the candidate raised to bring an end to the dissensions between the rivals and formed a new branch of the Arsacid line.
The effects of this internal strife were clear and twofold. Not only was the Parthian empire not able to capitalise on the seeming collapse of Rome’s eastern empire (following the invasion of Mithridates VI of Pontus), but their own position as the dominant power in the Middle East was severely challenged. Seeing both Rome and Parthia collapsing into civil strife, Tigranes of Armenia threw off the role of vassal state and made a bid to turn Armenia into the regional power. On the death of Mithradates II, and feeling that all personal ties were now broken, Tigranes launched an invasion of both the Parthian and Seleucid empires. Northern Mesopotamia, untouched for forty years, fell to the Armenians, as did the whole of the remaining Seleucid empire (see map 2). He invaded Media and burned the Parthian imperial palace there to the ground.91 The only check on the advance of the Armenian armies proved to be the arrival of the Roman armies in the region, in the 70s BC.
In 70 BC, the aged Sinatruces died and his son Phraates III came to the throne, ushering in a period of relative internal stability. The position he inherited, though far worse than the one left by Mithradates II, showed signs of improving, but only thanks to the actions of the Romans, as will be detailed later. Phraates’ reign came to a sudden end in 58/57 BC when he was murdered in a palace coup organised by two of his sons, Mithradates III and Orodes II. Once again the Parthian monarchy collapsed into instability and on this occasion, with Rome free of civil war, it gave their enemies the opportunity they had been looking for.
We can see that there are parallels between the eastward expansion of the Roman Republic and the westward expansion of the Parthian Empire, though they took different forms. Ostensibly Parthian expansion was created by a desire for independence, borne out of the revolt of the 240s BC and it was clear from the start that for Parthia to survive the Seleucid empire needed to be overthrown. Likewise, no conscientious Seleucid king would accept the loss of their eastern territories, not to mention the creation of a dangerous rival. Up until the end of the reign of Mithradates II, the viability of the Parthian state was still at stake. Unlike Rome, however, many of the Parthian problems were of their own making. Periods of expansion, under Arsaces I, Mithradates I and Mithradates II were all followed by periods of contraction. This was contrasted with the Roman Republic which expanded and rested, but rarely contracted (the Pontic invasion of 88 BC being the notable exception).
Central to this whole process was the Parthian monarchy. A strong monarch could utilise Parthia’s military and economic powerbase to dominate and ultimately conquer her neighbours in the east, which led to them becoming the superpower of the region. Yet a weak monarch, or a series of weak monarchs, could throw all this good work away, as happened in the 200s, the 120s and 70/60s BC. Nevertheless, despite the system’s unpredictability, the Parthians ultimately always seemed to find a monarch who could undo a period of decline and take the empire to new heights.
Thus, in the 50s BC a clash appeared to be inevitable between two seemingly unstoppable juggernauts, one driving eastwards and the other westwards. Neither had shown any inclination to live with a rival of equal power. The very existence of a state with the power to rival their own was enough for the other to feel threatened.
The Roman oligarchy saw any other powerful state as a threat to their security and a potential invader of Italy, as the recent experiences with Mithridates VI had shown. However, a threat to them was also seen as a golden opportunity for glory and economic gain, as the clash between commanders for the opportunity to fight Mithridates VI had also shown. Thus the Romans operated from a mixture of paranoia and opportunity. To the Parthian kings and the aristocracy any rival power was considered a threat to their existence and a potential invader of the Parthian homeland, as their recent experiences with Armenia had shown. Thus, both states would have felt threatened by the presence of the other, a situation that could only have a single outcome: war.