Zenobia `was accustomed to hardship, and many even thought her braver than her husband, for she was the noblest of all women of the east and ... the most beautiful.'
`So died Aurelian, an emperor who was necessary rather than good.'Anonymous author of the Historiae Augustae, fourth century.'
On the monuments commemorating his victory, King Shapur grasps Valerian by the wrist. Envoys were sent to the Roman's senior subordinate, Macrianus, but he refused even to discuss ransoming the captive. Valerian's son and co-ruler Gallienus was far away and never had the ability - and perhaps even the desire - to buy back or rescue his father. Valerian lived out the remainder of his life as a prisoner. Shapur was supposed to have employed him as a mounting block, stepping on the crouching Roman as he climbed on to his horse. One fourth-century source claims that when the emperor died, the Persians flayed his skin, painted it red and then hung it up in a temple as a trophy. The author was a Christian and his book recorded the grisly ends of all those responsible for persecuting the Church - something that Valerian had renewed - so perhaps he let his imagination run away with him. However, he did claim that the trophy was seen by Roman ambassadors in later years.
Shapur had won a great victory. City after city fell and was plundered. In time, the Persian army divided into smaller groups, and some began to make their way home with their spoils and captives. Simultaneously, the Romans started to recover and counter-attacked, winning a few skirmishes. Macrianus exploited these minor successes to declare his two sons joint-emperors - he was lame, so felt himself disqualified from such a public role. Taking his older boy and a large part of the army, he crossed into Europe and marched on Italy. They were destroyed by forces loyal to Gallienus in 261.3
The other main leader of the Roman recovery in the east was Septimius Odaenathus, and he stayed loyal to Gallienus. A Palmyrene nobleman - probably the third generation of his family to be Roman citizens - he had come to dominate his home city. He also pursued a career in imperial service, seems to have gained senatorial rank and may well have been governor of one of the Syrian provinces. Perhaps he was still in this office when he led troops against the Persians, although it is equally possible that he acted without formal power and simply as a prominent local man. His loyalties may not always have been clear, and one source claims that he sought friendship with Shapur. Scornfully rejected, Odaenathus won a series of victories over the Persians, hastening their retreat. With the invaders gone, he next suppressed Macrianus' younger son.4
Odaenathus was not content merely to expel the Persians from the Roman provinces, and in 262 he led a major offensive that got as far as Ctesiphon. This and a second expedition - probably in 266 - were no more than large-scale raids, but they helped to restore Roman prestige. Shapur remained on the defensive for the rest of his reign - he had already won enough victories to secure his hold on the throne. Gallienus granted Odaenathus a number of honours, and the titles of dux (a senior rank and the origin of the medieval `duke') and `commander of the entire east' (corrector totius orientis), which probably gave him authority over individual provincial governors. Odaenathus had already styled himself `lord' of his home city of Palmyra. Now he aped the Persian monarch and was named `king of kings'.'
In spite of the grandeur of such titles, Odaenathus never claimed imperial status. He guarded the frontier with Persia and put down any challenge to Gallienus, but, rather like the leaders of the `Gallic Empire', he made no attempt to expand the territory under his control. For six years he was effectively in control of much of the eastern part of the empire. As far as we can tell he seems to have governed competently - certainly, virtually all of our sources are favourable to him. Even so, he and his eldest son Herodes were murdered in 267 by one of his cousins. It was said that the dispute began with a squabble over precedence during a hunt - Odaenathus, like many other aristocrats, was a very keen hunter. Perhaps there was no more to it than a relative's anger over a public humiliation, but then and later some people have suspected a deeper, more political conspiracy.
Whatever the truth of the matter, its sequel is not in doubt. Power now passed nominally to Odaenathus' younger son Vaballathus, but since he was only a child, effective control lay with his mother, Zenobia. She was Odaenathus' second wife, and the fact that the murdered Herodes was the product of an earlier marriage added to the rumours of a palace conspiracy. Vaballathus was styled `king of kings' and 'commander of the entire east'. These were exceptional times and Odaenathus had had an exceptional career, holding power over such a wide area for a long period. His local connections had added to his prestige, but ultimately he had been a Roman official holding rank granted to him by the emperor - even if in truth Gallienus may have had little choice in the matter. This was an appointment, and there was absolutely no precedent within the Roman system for such a rank to be passed on to an heir, or indeed held by any child. For the moment it was tolerated - Gallienus had other, more immediate, priorities, as did his successor Claudius II - and so for the next few years a woman controlled the greater part of the eastern empire.'
The Queen of Palmyra
Palmyra - Tadmor in its people's own Aramaic tongue - grew rich through trade, but it existed in the first place because of water. Its springs and wells were rare things in the Syrian desert and its Latin name probably meant the `place of palm trees'. Early in the first century it was brought under Roman control, but the trade links with Parthia remained strong. Rome's empire demanded luxuries from the east in ever greater quantities and Palmyra became a vital staging point for the great caravans that crossed the deserts. Camels figure prominently in Palmyrene art, reflecting their importance in making the desert crossings. Virtually all the trade came via the Euphrates. Some caravans stopped at Dura Europos, about 130 miles away, where the river was closest, but ultimately most went further down the Euphrates, to the trading ports lower down or even to the Gulf itself. Inscriptions record Palmyrene merchants who sailed from there to India. Others provide more detail about how the caravans were organised and protected, for the high value of the spices and other luxuries they carried were a temptation to attacks from raiders.7
In Odaenathus' day, Palmyra was a large and magnificent city, and its romantic desert ruins created something of a sensation when they were discovered by Europeans in the middle of the eighteenth century. Its greatest monument was the first-century Temple of Bel, displaying a mixture of Roman, Greek and local styles in its design. In time the city acquired most of the grand buildings of a Greco-Roman city, with the exception of the quintessentially Roman bath house and amphitheatre, or the equally Greek gymnasium, none of which obviously had much appeal to local tastes. A range of languages was in daily use and a high proportion of monumental inscriptions were bilingual, most often in Greek as well as Palmyrene. Latin seems always to have been fairly rare, even after the city gained the status of a Roman town under Hadrian. As traders, Palmyrenes spread widely. There were many in Rome - and we have already encountered Barates, who left a memorial to his British wife on Hadrian's Wall. Others were at least semi-permanently resident in the communities of the Euphrates Valley, some even becoming officials of the local leaders!
Odaenathus' family was one of several to become massively rich through the caravan routes, but it is hard to say whether Palmyra's aristocracy was created or merely made even more powerful by trade. There is certainly no evidence for Odaenathus coming from a longestablished royal family. The city's chief magistrates were called `generals' (strategoz), and although this old Greek title was common in many cities for civil officials, in Palmyra they still had military functions. Strong forces were maintained to protect the caravan routes, in addition to the Palmyrenes who served in the regular Roman army like the cohort at Dura Europos. Palmyra was famous for its archers and its heavy cataphract cavalry, but presumably there were also other lighter horsemen and probably camel riders more suited to escort duty. Odaenathus combined these troops with regiments from the Roman army when he fought the Persians and suppressed the usurper.'
Zenobia was probably in her late twenties or early thirties when her husband was killed. Like him, she seems to have come from the Palmyrene aristocracy and was a Roman citizen. Although she educated her children in the language, she is said to have had limited knowledge of Latin herself, but was fluent in Greek and Egyptian, as well as Aramaic. As queen she claimed descent from the Ptolemaic and Seleucid royal houses of the Successor kingdoms established by Alexander the Great's generals. In particular, she seems to have encouraged comparisons between herself and Cleopatra. Several sources emphasise her beauty as well as her intelligence, courage, powers of endurance and fondness for masculine sports like hunting. Unusually for a woman - especially an eastern woman - they do not depict her as sexually voracious, and instead they emphasise her chastity, sometimes to an extreme degree.'°
For several years after Odaenathus' murder, no emperor in Rome was in a position to do anything to bring the eastern provinces under direct control. Vaballathus was proclaimed with the same titles and authority as his father, but again for several years these stopped short of claiming imperial dignity. An inscription from 271 describes the boy as the `restorer of the whole east'. Up until the accession of Aurelian the coins minted in the areas controlled by Zenobia and her son followed standard patterns. A few months later they began to produce coins with two `heads'. A bearded and crowned Aurelian was on one side with his full imperial titles. On the other side was a beardless Vaballathus, styled `most distinguished man' (i.e., a senator), `king' of Palmyra, `victorious general' (imperator), and `leader of the Romans' (dux romanorum). It's hard to tell whether or not this actually presented the boy as Aurelian's junior co-emperor.
As Vaballathus' prominence grew, so did the regions under his control. Forces loyal to him had already campaigned to the south, attacking Arabia. An inscription from Bostra records the restoration of a temple to Jupiter Hammon, `which had been destroyed by Palmyrene enemies'. In 27o an army invaded Egypt, defeating a force led by the provincial governor. The bulk of Zenobia's troops then withdrew, but returned to suppress a rebellion. Oddly, this does not seem to have been seen as a decisive break with the emperor in Rome. Like the forces of Odaenathus, Zenobia's army seems to have been a mixture of Roman regulars and Palmyrene soldiers. Yet its senior commanders, Septimius Zabda and Septimius Zabdai were both Palmyran, and also Roman citizens. Zenobia does seem to have preferred to rely on men from her home city, who may well have been relatives."
The queen now controlled Syria, Egypt, much of Asia Minor - although locally raised forces had repulsed her men in Bithynia - and some of Arabia. The culture of her court certainly had a strong Palmyrene flavour, but was not exclusively so. One of her main advisers was the widely respected philosopher Cassius Longinus from Emesa, who had taught rhetoric at Athens. There is no evidence for an attempt to spread Palmyrene or, indeed, any sort of distinctively `eastern' culture throughout the areas under Zenobia's control. Instead, government remained essentially Roman, and Roman titles were always paraded alongside specifically Palmyran rank.'3
In 271 Vaballathus was finally proclaimed emperor. Aurelian's face disappeared from coins produced by the official mints in Antioch and Alexandria, and instead all coins carried the boy's image, sometimes along with that of his mother. He was given the title Augustus, while Zenobia became Augusta. It was an open declaration of rebellion against Aurelian, not against Rome, and Vaballathus was simply presented as the legitimate emperor. Elagabalus and Severus Alexander offered precedents for boy emperors, as they did for emperors from Syria and the behindthe-scenes rule of women. The situation was very similar to the Gallic emperors and, just like them, Zenobia made no effort to expand her territory further and take over the rest of the empire. This does not mean that they made no claim to the other provinces, merely that they did not choose to take them by force at this stage. Perhaps Zenobia hoped to negotiate the acknowledgement of her son as co-ruler with Aurelian, who was childless and so had no obvious heir. If so, then she was disappointed.14
The Restorer of the World
In 272 Aurelian led an army into Asia Minor and at first encountered virtually no opposition. When Tyana closed its gates to him, he angrily swore `not to leave even a dog alive' when he captured the place. In the event the city was quickly betrayed by a man who let Aurelian's soldiers in. The emperor executed the traitor, feeling that a man who would betray his own home could never be trusted, but he refused to let his men sack the town. Instead, he told them to slaughter all the dogs. Having recovered Asia Minor, the army moved south into Syria. The first major clash was near Antioch - probably at Immae where Macrinus had been defeated by Elagabalus more than fifty years before. Worried by the enemy's strong force of cataphract cavalry, Aurelian sent his own lighter horsemen forward to meet them, with orders to give way as soon as the enemy advanced. The Romans did as they were ordered, luring their heavier opponents into a disordered pursuit. Soon they were exhausted from the heat of the sun and the weight of their armour, and were cut to pieces when the Romans rallied and turned on them. Zenobia's army retreated to Emesa - a captive resembling Aurelian was dressed up as the emperor and paraded through Antioch to prevent the people from switching sides before they could escape."
Aurelian pushed on. One hilltop town was stormed when his soldiers advanced up to its walls in the famous testudo or tortoise formation, their overlapping shields held over their heads to protect them from missiles. Soon afterwards he caught up with the enemy army and fought another battle at Emesa. Once again the Roman cavalry were ordered to feign flight and lure the enemy cataphracts into a trap. However, either the Palmyran commanders had learned from their earlier mistakes or the manoeuvre was not carried out so carefully, for this time the cataphracts caught up with the retreating Romans. The battle was won by the Roman infantry, who provided determined support. Aurelian's army included a broad range of troops he had brought with him from Europe, as well as men from the nearer provinces. It is noted that he had a contingent from Palestine - most probably regular units stationed in the region - who carried clubs and maces as well as their normal equipment, and that these proved particularly effective against the armoured enemy. It is more than likely that regular units were still fighting for Zenobia, but obviously it was in the interest of Aurelian to emphasise the foreignness of his enemies. Augustus had done much the same when he fought Antony and Cleopatra."
After this victory Aurelian began to besiege Palmyra itself. Around the same time an army led by one of his commanders retook Egypt. At Palmyra Zenobia despaired, sneaked out of the city with just a few followers and set out over the desert on camels. It was said that she hoped to escape to Persia, but instead she ran into a Roman patrol while crossing the Euphrates and was captured. Abandoned by their queen, the forces in the city soon surrendered and were spared the horrors of a sack. Aurelian was merciful to Zenobia, just as subsequently he would be generous to Tetricus. Instead, the chief blame was placed on her advisers. Cassius Longinus was one of those executed, and was said to have met his fate with great dignity. There is no record of what happened to Vaballathus, which gives some indication of his lack of real importance .17
The rebellion was not quite over. When Aurelian withdrew the bulk of his forces, a new emperor was proclaimed by the Palmyrenes in 273. The Roman army returned and stormed the city, and this time its inhabitants paid a heavy price. It was the end of Palmyra's golden age. It shrank in size and became little more than a garrison town - finally getting a bath house to meet the needs of the soldiers. The trade routes shifted away, most probably hastened by the ruin of Dura Europos some years before, and the source of Palmyra's prosperity vanished. Another rebellion in Alexandria was also suppressed, but it is less clear whether or not its leader was seeking imperial rule or had more modest objectives."
Aurelian was back in Rome in 274 and celebrated the grandest triumph seen for many years. Tetricus marched as captive in the parade, as did Zenobia, so laden down with heavy jewellery and golden chains that she struggled to walk. The former emperor of the Gauls then went on to his administrative post, becoming corrector of Italy. Accounts differ over Zenobia's fate, but the most convincing - as well as the most appealing - is that she was married to a senator and lived out her life in comfortable peace. Over a century later her descendants were well-established members of the senatorial elite and proud of their famous ancestor.'9
The treatment of Tetricus and Zenobia emphasises that they were not seen as nationalist leaders who wanted to split away from the empire. The Gallic emperors and Vaballathus and his mother were usurpers, but ones who showed considerable restraint and did not focus their main effort into destroying Roman rivals. Instead, they concentrated on gaining control of parts of the empire that central authority of the `legitimate' emperor in Rome struggled to govern and protect. For over a decade a greater degree of normality and the rule of Roman law and administration was preserved than the weakened central government could have provided. All of these leaders were ambitious, and doubtless hoped eventually to secure through negotiation or warfare power over the entire empire. Had any of them done so, we would doubtless have talked about the strong man - or woman - whose ambition had been necessary to restore the empire.
Aurelian was praised for this, even in sources emphasising his ruthlessness and cruelty. Defeating Zenobia and Tetricus, and bringing the provinces they ruled back under the control of central government, were the great achievement of his reign. For a short while the empire was reunited under a single emperor. They were not the only wars fought in his reign, and his first two years in power were spent meeting various barbarian incursions. In 270 or 271 raiders again reached Italy and the emperor hastened back from the Danube to deal with them. Aurelian's column was ambushed and badly beaten near Placentia (modern Piacenza) on the Po. This was a rare defeat and he quickly recovered to smash the enemy in two subsequent battles."
Aurelian spent the bulk of his reign away from Rome. He was there in 271, crushing a riot led by workers in the imperial mint, which almost became an open rebellion. It had been provoked by the banning of long-established and highly profitable corruption within the system. Thousands may have died in the fighting before the trouble was crushed. Aurelian was ruthless in quelling this opposition, but seems to have sensed that Rome felt less secure. Therefore, work began on a massive circuit wall, more than I21 miles in length and almost 20 feet high. Unlike many other cities that shrank in size when they were fortified, Rome's new defences virtually enclosed the entire city. Apart from providing this protection, the emperor also reformed the system for supplying citizens resident in the city with free bread. He regulated the weight of loaves, made the right hereditary, but also extended it to the entire free population of the city. Septimius Severus had also introduced a free distribution of olive oil, much of it from Spain. Aurelian confirmed this and also made salt and pork a regular part of the distribution. Wine was also provided by the state, although this was not free, but simply sold at a fixed and low price."
The emperor boasted of a special relationship with the `Unconquered Sun' (Sol Invictus) and in 274 dedicated a great temple to the god in Rome. Such claims were not in essence new, and the cult was not unpalatable in the same way as that of Elagabalus. Aurelian's beliefs may have been genuine, and it was certainly no bad thing politically if an emperor's subjects could be persuaded that his rule was divinely supported. No other cults were suppressed. Some later Christian sources claimed that Aurelian was planning a new persecution of the church in the last months of his life. The last empire-wide attack on the Christians had come under Valerian. Unlike Decius, he had specifically targeted the Christians, or rather their leaders. These were to be arrested and executed if they did not publicly abandon their faith. Any who were senators, equestrians or held official office were to be stripped of their status. The Senate seems to have written to Valerian to discover what they were then supposed to do with such men. Christian meeting places may also have been seized.
Perhaps Valerian was not interested in the beliefs of poorer Christians or he may well have hoped that dealing with their leaders would severely reduce overall numbers. We have most evidence for the impact of the persecution in North Africa, where the prominent theologian and writer, Bishop Cyprian, was one of the victims. Gallienus either was less committed to the purge or did not want to alienate any group after his father's capture by the Persians. He issued a new proclamation ending the persecution and granting the Christians freedom of worship. In the eastern provinces Odaenathus and especially Zenobia seem to have had a benevolent attitude and some interest in Christians, Jews and the new faith of the Manichaeans. Christians practised their religion openly, had well-known and public places of worship, while their leaders were often prominent local figures."
After the recapture of Antioch, Aurelian received an appeal from Christians there who were engaged in a dispute with their own bishop, Paul of Samosata. For some time he had preached doctrines considered to be heretical, most importantly denying the divinity of Jesus. After an earlier church council he had publicly renounced this view, but subsequently changed back to his original position. Expelled from his see, he was reinstated by Zenobia, having appealed to her as the closest representative of imperial authority. Now, he refused to leave the building used as the church meeting place and was also accused of living in lavish splendour, attended by followers just as if he were a government official. It was normal for representatives from cults, or indeed any other community or group, to seek a judgement from the emperor when they were unable to resolve disputes to their satisfaction. Even so, it is striking to see the so recently persecuted Christians appealing to an emperor. Aurelian decided against Paul and ordered his expulsion from the church building. The incident gives no hint of a would-be persecutor."
Murder and Civil War
Aurelian was a successful emperor, but most of his closest officers and staff feared him, and some hated him. In 275 he was in Thrace, perhaps on his way eastwards to mount an expedition against the Persians, when he was murdered. None of the conspirators appear to have been especially senior, and stories circulated that they had been duped into fearing for their lives by one of the emperor's secretaries. They had no candidate for the throne and, in any case, would have carried no weight with the army as a whole, since the rank and file remained deeply attached to Aurelian. There was a strange pause while senior army officers chose a successor. Later tradition magnified this into a six-month interregnum, with Senate and army politely inviting the other to name a new emperor. More probably there was at most a matter of weeks before the aged Tacitus (fully, Marcus Claudius Tacitus) was named. One source claims that he was seventy-five, but this may well be an exaggeration. He was another of the successful equestrian officers from the Danubian provinces, who had subsequently received senatorial rank and then retired from active service to live on an estate in Campania.24
Taking power at Rome late in 275, Tacitus went on campaign early in the next year, going to Asia Minor, which was again plagued by attacks from seaborne raiders, many of them Goths. Some of the barbarians claimed that they had originally assembled to answer Aurelian's demand for them to serve as auxiliaries in his Persian expedition. Perhaps this was just a pretext, but equally there may have been a genuine misunderstanding. Most of the warriors turned to plundering and Tacitus attacked them, winning a victory - something of great value for a new emperor. Less successful was his choice of his relative Maximinus as governor of Syria, who proved so brutal and corrupt that he was quickly murdered. Fearing punishment, the same army officers then killed Tacitus.2s
The praetorian prefect Florian (fully, Marcus Annius Florianus) was now named as emperor. Not everyone agreed with his nomination and a senior provincial commander Probus (fully, Marcus Aurelius Probus) was able to rally strong forces from Egypt and Syria to back his own claim. Florian had been made emperor in June. By the end of summer he was dead, killed by his own men when they saw the enemy army approaching them near Tarsus. Yet another equestrian officer from the Danube, Probus was to spend the bulk of his six-year reign on campaign, fighting on the Rhine and Danube, as well as in Asia Minor and Egypt. Not all of the enemies were foreign. There were short-lived usurpations in Syria and more serious ones on the Rhine and in Britain, which were only defeated after some effort."
Gaul was plagued by large bands of robbers. There was also a revolt in Isauria in Asia Minor, led by a bandit leader called Lydius, but this is unlikely to have been a bid for imperial power. The inhabitants of this mountainous region had a reputation as semi-barbarians, but excavations at the city of Cremna suggest that this was greatly exaggerated. Even so, banditry was common in the area and they seem to have taken the opportunity of the disturbed times to raid nearby communities. Probus sent the equestrian governor of Lycia and Pamphylia, one Terentius Marcianus, against the rebels, who were driven back behind Cremna's walls.
What followed demonstrated that the Roman army still maintained much of its skill in siege warfare. The only viable approach to the city was on the western side, and the attackers began by building two long, dry-stone walls to defend against sallies and prevent the defenders from escaping. Heavy catapults were sited on the inner wall and began to bombard the city's fortifications. Then the Roman troops started work on a huge mound little more than 20 yards from the city wall. It was used as a platform for more heavy artillery, but could readily have been converted into an assault ramp at a later stage. Lydius' men responded to the threat by building a much smaller mound of their own behind the wall, for there was a great advantage to having a higher platform. Yet they could not match the regular army's engineering skill or manpower, and even though the city was higher up the slope than the Roman mound, this soon equalled the height of their own platform. Heavy stones - approximately 17-18 inches in diameter and weighing 200-270 lb - from the Roman artillery have been found amongst the debris of the wall nearest to the mound. One tower was smashed, another partially collapsed and had to be hastily repaired. Lydius was shot by a bolt from a ballista aimed by the man who had been in charge of his own artillery, but who had deserted after being flogged. Either his death, or the ominous height of the Roman mound, prompted the city to surrender.27
The Roman army was still highly effective when its troops were properly trained, kept supplied, decently led and available in reasonable numbers. Under Probus the Romans won many victories and suffered very few defeats. By the standards of the period he had a long and successful reign, yet it may be that most of the successes were won by his subordinates. He does not seem to have been popular with the army, or at least its officer corps, in part because he employed the troops as a labour force on civil engineering and agricultural projects. There was a long tradition of such work in the Roman army, but it had probably become far less common in recent generations. In 282 Probus was murdered by a group of officers and replaced by his praetorian prefect Carus (fully, Marcus Aurelius Numerius Carus), who ruled jointly with his sons Numerian and Carinus. Carus was another equestrian officer, although unusually for the period his family came from Gaul and not one of the Danubian provinces.z8
Probus had probably been preparing an expedition against Persia before his death, and in 283 Carus and Numerian advanced into Mesopotamia, which had been more or less under Persian control since 260. The offensive went well and the Romans seem to have won a major battle. Once again a Roman army reached Ctesiphon and this time the city was captured. Carus pushed on, but sometime near the end of the summer died suddenly. Sources claim that he was killed when his tent was struck by lightning, but many historians suspect this was simply a cover story. Perhaps he died of disease, or more likely was murdered. Numerian succeeded him and ruled for most of the next year. The Persian War was abandoned, but as the army withdrew the young emperor fell ill with an eye infection. He was then murdered by the Praetorian Prefect Aper, who managed to conceal the act by pretending that the emperor was simply sick and forced to stay in a covered litter. Eventually the smell exposed the deception, and the army's officers refused to rally behind Aper. Instead, they chose one of their number, Diocletian (fully, Caius Valerius Diodes), as emperor, yet another equestrian officer from the Balkans. He may have had a secret link with Aper, but his first public act after his proclamation on 20 November 284 was to stab the prefect to death, ensuring his silence."
In the meantime, Carus' other son Carinus faced a challenger in Europe when Sabinus Julianus rebelled in Pannonia. In 285 Carinus smashed the enemy in battle near Verona, but by this time Diocletian's forces were also advancing from the east. A few months later the rivals confronted each other close to where the River Margus joins the Danube. The battle was hard-fought and may even have been going Carinus' way, when some of his own officers decided to switch sides and murdered him. One of the motives was said to be the emperor's frequent seduction of other men's wives. For the moment, Diocletian was sole emperor. He would prove to be the most successful ruler the empire had had since Septimius Severus, another man who reached power through civil war.3°
Carus' invasion had struck a Persia that was itself divided as rival claimants fought for the throne. Shapur I had died in 272. Between them, he and his father had ruled for almost half a century since the defeat of the Parthians in 224. Both were strong leaders and skilful commanders, and together they firmly established their dynasty, but it would be many years before other Persian kings would prove as long-lived and successful. Shapur's son died only a year after becoming king, and his grandson only lasted three. When this man's son, Vahran II, succeeded, the royal family divided, as another branch backed a different candidate and rebelled. It was a sign of the achievement of Ardashir and Shapur that no challengers emerged from outside the Sassanid family. Yet the feudal nature of the kingdom, and its heavy reliance on family members as local kings of each region, always left open the possibility of competition within the royal house for supreme rule."
Modern historians are inclined to see Sassanid Persia as a far more formidable and aggressive opponent than the old Parthian Empire it supplanted. Some talk blithely of a new superpower, posing such a threat to the Romans that they were forced to massively increase their military spending. The cost of this placed a huge strain on the empire's economy and encouraged dramatic political and social changes. Therefore, the radical changes in the State - many ofwhich would occur or be completed under Diocletian - were a necessary if traumatic response to a new situation."
This is a convenient theory, but very difficult to justify. Much of it is based upon the victories won by Shapur I, which were undoubtedly spectacular, but need to be placed in the context of the situation and his own aims. In spite of the boasts of their ambassadors, there is not a shred of evidence for the Persians ever genuinely seeking the reconquest of the old Achaemenid Empire. They did want to restrict Roman power in the areas bordering their lands - Rome had never been a comfortable neighbour and had over time gradually expanded its territory. The Sassanids also needed to eradicate the Arsacid monarchs in Armenia and anyone else likely to challenge their hold on the kingdom. Ardashir and Shapur took advantage of Rome's weakness to dominate the border regions and also to attack the empire itself.
However, this was never a question of permanent conquest. The Persians lacked the strength to achieve this and probably never even considered long-term occupation. Invading armies could and did plunder the Roman provinces over a wide area. Great cities like Antioch fell and were looted, but there was never any question of the Persians holding on to them. Another important objective was the taking of captives in large numbers, and Shapur took many thousands. These were taken deep within his kingdom and settled so far from the borders as to make escape impractical. There they laboured on major engineering projects for the king, building cities, as well as dams and irrigation systems. The results increased agricultural yields on the royal lands, further adding to the king's wealth and power.33
The Persian army was effective in the right circumstances - although it is hard to say whether it really differed to any great degree from later Parthian forces since we know so little about these. There is more evidence for some skill in siege craft than had ever been shown by the Parthians, but this should not be exaggerated. Ardashir and Shapur led a very good army, which had carried them into power. Most later kings would not have so many experienced and confident soldiers under their command. It was not a standing army and relied on a part-time feudal element unsuited to garrisoning captured cities. After a big success, many of the contingents would start to disperse and return home with their spoils, leaving the army vulnerable.
As far as we know, after 26o Shapur made no aggressive moves against the Romans. Odaenathus raided as far as Ctesiphon and does not seem to have suffered a serious defeat. The Persian king did not attempt another major attack, even though the Roman empire remained divided. In part this was because Odaenathus and subsequently Zenobia maintained a strong army, although it is doubtful whether this was as powerful as the regular forces in the eastern provinces in more peaceful times. Shapur may have had problems in other parts of his broad realm - it should never be forgotten that he had other borders apart from the one with Rome. More importantly, he had already achieved all that he needed from fighting the Romans - three emperors vanquished and humiliated, armies crushed, long lists of cities taken and plunder and captives in abundance.
The Romans were a powerful and often aggressive neighbour. They posed a threat against which Ardashir and Shapur could unite the subjects of their newly won kingdom. Both men needed victories to secure their hold on power, and a weakened and divided Rome offered an ideal target. Their successes fostered new wars, as the Romans characteristically sought vengeance by invading Persia. Managing to defeat these attacks - or at the very least survive them - brought more glory to the monarch, as well as the reason and opportunity for fresh expeditions against the Roman provinces.
Persia was not the equal of the Roman Empire, and to see Rome and Persia as rival superpowers is deeply misleading. After Rome, Persia was undoubtedly the strongest state in the known world, far greater than any barbarian tribe or even confederation of tribes, but it still had nothing like the wealth, resources and professional army of the Roman Empire. Ardashir and Shapur fought to win and hold on to power. The appearance of such formidable kings and their need for fresh victories coincided with a time of Roman weakness through division and civil war. When Shapur was more secure on the throne he became far less aggressive. Later kings were not so gifted as commanders or were too busy fighting internal rivals to attack Rome. They also faced stronger, more united opposition as civil war became less frequent amongst the Romans themselves. The Persians were unable to repeat the successes of Shapur for many generations.