With the old alliance of Sparta and Athens that had been formed during the Greco-Persian wars officially dissolved, the Athenians prepared for a general conflict with the most militarily powerful of their neighbors. Like the Messenians themselves, it is likely that the Athenians wanted to execute their plans as quickly as possible in order to exploit the temporary weakness of Sparta after the natural disaster that had, for once, managed to loosen the absolute dominance of Sparta over the Peloponnese. Three new alliances were quickly formed by Athens in order to improve its strategic position against its new enemies. The first, with the northern state of Thessaly, was likely meant simply to bring in additional troops in support of Athens from a state that had never been allied to Sparta and so had no lingering ties to it. The second two, however, were selected more for their enmity toward Sparta and their locations than for the simple purpose of increasing the size of the new allied army. These two states were Argos and Megara. Argos had been a major source of opposition to Sparta in the Peloponnese since before the formation of the Peloponnesian League, and was more than willing to lend its help to Athens in a war against its oldest rival. Megara, on the other hand, had a more complex history with Sparta. The Athenian alliance with Megara was not concluded until it had defected from the Peloponnesian League, of which it had long been a member. This move, supported by Athens, brought it into direct conflict with the other members of the league and started the event known as the First Peloponnesian War sometime in 460 BCE.
The first three years of the war were largely marked by the conflict between an Athenian-supported Megara and the city-state of Corinth, the most influential member of the Peloponnesian League after Sparta itself. By 457 BCE, however, Sparta had managed to rebound from the earthquake enough to bring its own military into the war. Its first move was to secure Doris, a city-state allied to the Peloponnesian League which had come under an attack from the Phocians, who had fallen into the war on the Athenian side. After having successfully secured Doris from its Phocian enemies, the army made up of Spartans and their allies and led by a commander by the name of Nicomedes turned to invade Boeotia, prompting the Athenians to mobilize their armies. At the same time, there is said to have been at least some possibility of a revolution in Athens, as a group of treacherous Athenians had engaged in negotiations with Spartan representatives to allow them to seize the city and impose the oligarchical form of government favored in Sparta in place of the Athenian democracy. Exact details of this plot are not known from surviving histories, and it does not appear that it was a serious threat to the power of Athens unless the Spartans themselves could back it up militarily.
The forces under the command of the Spartans were cut off by the Athenians, who positioned themselves so as to prevent their return to the Peloponnese via either land or sea without a substantial fight with an Athenian force. The two forces would eventually face off against each other at the Battle of Tanagra, with the Spartan forces still trapped in Boeotia. The battle was overly costly for both sides, but the need for the Spartan army to withdraw itself to friendly territory would have been great enough to justify it, as a defeat in Boeotia would almost certainly have tilted the balance of the war in favor of Athens. A narrow Spartan victory (though it can only be considered as such in allowing the Spartans to achieve their objective of successfully breaking through the Athenian line and returning to the Peloponnese) ensued, and the Spartan-led army removed itself from Boeotia, which promptly fell back into Athenian control.
Following this attempt by the weakened Sparta to reassert itself as the major power in Greece, the Athenians would go on to achieve several victories in the First Peloponnesian War, particularly along the coast of the Peloponnese, which was heavily targeted by the Athenian fleet. By 451 BCE, however, Athens was forced to enter into a truce with Sparta, as a campaign that they had been waging against the Persian empire, now under the rule of Artaxerxes I, in Egypt had ended in the destruction of a large segment of the Athenian navy. Indeed, Sparta had, at one time, been asked by a representative of the Persian empire to launch an invasion into Attica and attack Athens directly in order to force the recall of this expeditionary force, but Sparta had not consented, likely because it was still weakened too greatly to engage Athens head-on.
The eventual result of the First Peloponnesian War was a five year truce between the two city-states, which was then followed by a final attack on Attica led by the son of Pausanias. This final action of the First Peloponnesian War was apparently successful enough to convince Athens that a general war with Sparta was too costly to pursue, as it soon renounced many of its territorial claims, including those in Megara, in exchange for the Spartan withdrawal from the city of Aegina. These agreements were made as a part of the Thirty Years Peace, the name given to the treaty between the two. The peace agreement ultimately ended the conflict, though tensions between Sparta and Athens would remain and continue to affect the history of Greece, leading to the better-known war that could come to ultimately be called the Peloponnesian War (from this point forward, all uses of this term refer to the later war, rather than to the preliminary First Peloponnesian War).
Even during the period of far less than 30 years that it held, the Thirty Years Peace was, at best, an unstable truce that came close to breaking down on multiple occasions. The first was in 440 BCE, when the island of Samos, previously an ally of Athens, decided to break away from Athenian influence and attempted to enlist aid from Sparta. Though it was strongly considered, the Spartans declined to support Samos in its bid for independence from Athens. Next came a struggle between Athens and Corinth, the latter of which was still a leading member of the Peloponnesian League and an ally of Sparta. Corinth had come into conflict with one of its own subsidiary states, Corcyra. Despite the matter being wholly the concern of the states of the Peloponnesian League, Athens contributed some aid to Corcyra, supporting it against the strongly Spartan-allied Corinth. This and other interventions on the part of Athens would lead many of the Peloponnesian League members to voice their dissatisfaction with the role that Sparta, which was bound by the treaty to a peace with Athens, was playing. In 432 BCE, the Spartans convened a council of representatives from their allied city-states, and listened as these representatives presented their grievances. Though the Thirty Years Peace provided for diplomatic resolution of such disagreements, Sparta ultimately decided that Athens, in providing support for Corcyra and for intervening in the internal matters of the Peloponnesian League, had already violated the treaty. By this logic, Sparta was no longer bound to peaceful relations with Athens, and the Peloponnesian War became clearly imminent.
Throughout 431 and 430 BCE, Spartan forces conducted heavy raids into the lands that surrounded Athens under the command of the Spartan king Archidamus II, who had been an instrumental figure during the First Peloponnesian War and may have, in his earliest years, been one of the leaders that had helped rebuild Sparta after the earthquake in 464 BCE. The early years of the war, however, were far from a full-scale conflict. Indeed, these Spartan raids into Attica were usually brief and rarely did any significant damage to Athens directly. Athens, at this time, was under the command of Pericles, perhaps its most famous leader and an able general in his own right. By maintaining strong defenses at Athens, Pericles was able to easily ride out the onslaught of the Spartan forces during this early period of the war. On the Athenian side, these early years were equally fruitless. While Sparta was in its military element on land, Athens was by far the greater sea power. Mobilizing its navy in 431 BCE as a countermeasure against Sparta's land incursions into Attica, Athens staged a series of sea raids on the coastal areas of the Peloponnese. Like Sparta's efforts, however, these attacks were largely unsuccessful in producing any real gains against the enemy.
In either 427 or 426 BCE (more likely the earlier, but the chronology is not sufficiently precise to say with certainty), Archidamus II died, leaving one of the kingships of Sparta to his son Agis, who then became Agis II. Under Agis, the assaults into Attica continued, though more vigorously than before, as permanent positions were at last set to give the Spartans strategic points from which to strike at their enemy. In the next year of the war, however, Athens would begin to gain the upper hand. In 425 BCE, an Athenian general named Demosthenes landed a fleet on the coast of Messenia, bringing their military power into an area of Spartan control that, even at the best of times, was a source of potential revolution. Establishing a base at Pylos, where they were able to cut off a Spartan force stationed on the nearby island of Sphacteria, this Athenian fleet was able to force the Spartans to withdraw from their expeditions in Attica for fear that the Messenians might yet again engage in a general uprising. These Spartan soldiers would eventually be captured by Cleon, the general who had succeeded Pericles as the leader of Athens after his death in 429 BCE. With the capture of these soldiers, of whom roughly 120 are thought to have been full-fledged Spartan citizens, Athens gained a great measure of power over the conflict by threatening to execute them.
Sparta, however, would soon find a way to restore the balance of the war, if not to defeat Athens altogether. A Spartan general by the name of Brasidas took a force of 1,700 men northwards to once again put military pressure on Athens from within its own territories. Although his force was small, Brasidas proved himself able to accomplish much with what he was given, successfully convincing many smaller cities allied to Athens to revolt against it. Among the cities that he was able to sway to Spartan control was Amphipolis, which was the site of much of the silver mining of the Athenian-controlled lands. This city could not be let go, as the economic implications of its loss for Athens would have been great and far-reaching.
Already, peace negotiations between Sparta and Athens were beginning. Both had seen losses as a result of the war, and both sides must have been aware of the massive damage that they would incur in a full-scale war with the other. The Spartan taking of Amphipolis was probably the event that secured the peace process, but Cleon would make an attempt to retake the city before a peace was made with Sparta. The first effort to retake the city was led by the Athenian general-turned-historian Thucydides, whoseHistory of the Peloponnesian War is the best direct source of information regarding the earlier years of this war. Another attempt was made, this time led by Cleon himself, who would die trying to retake the Athenian mining center before a peace was negotiated by the factions in both Athens and Sparta who wanted a treaty to be solidified. This loss was matched on the Spartan side by the death of Brasidas during the Athenian attempts to retake Amphipolis.
In Sparta, Agis II's colleague Pleistoanax, who had been banished from Sparta during the later years of the First Peloponnesian War, returned to take his place as the elder king and strongly pursued peaceful relations with Athens. The peace that was reached between them, called the Peace of Nicias for an Athenian general who had sponsored and supported it, would result in a tense period of greatly lessened hostilities after its adoption in 421 BCE. Thus ended the first leg of the Peloponnesian War, which is sometimes referred to as the Archidamian War, named for Archidamus II, under whose rule it had begun.
The peace came with no small price for Sparta, which endured dissent from many of its allies in the Peloponnesian League over its decision to enter into the treaty with Athens. Corinth, in particular, was not in support of the peace with Athens, and even pursued ties with Argos, the traditional rival of Sparta in the Peloponnese, after the peace went into effect. Nevertheless, Sparta and Athens would manage to hold this tense peace together for a period of about seven years, until it would begin to fall apart in 414 BCE.
Intriguingly enough, the cause for the first near breakdown of the peace would be less driven by the momentary political tensions between Athens and Sparta than it was by the ancient ethnic tensions between their two respective groups, the Ionians and the Dorians. A war had broken out in Sicily between the city of Syracuse, which was Dorian, and the Sicilian allies of Athens, who were Ionians. At the urging of Corinth, which had swung slightly back into Sparta's camp after a recent Spartan conquest of Argos, Sparta rallied to defend Syracuse from the Athenians. Interestingly, this put the Athenians and Spartans in a direct military conflict with each other without technically violating the peace agreement or putting the two states into a general war with each other. However, this would be a short-lived state of affairs. The political tensions between Athens and Sparta were, to say the least, too great to remain unresolved.
In 413 BCE, Sparta once again launched an incursion into Attica, even as the war in Sicily was still ongoing. Sometime near the end of that year or at the beginning of the next, however, the entire force of Athens that had been fighting in Sicily was defeated and largely destroyed. Most importantly, this included a huge portion of the Athenian navy, which had always been their main advantage against the Spartans, who were masters of land warfare. Following the defeat of Athens, which had come at the hands of a fleet from Syracuse that had been hastily constructed specifically for the war, Syracuse reciprocated Sparta's support by lending this new naval force to the Peloponnesian League. Aid also came, rather remarkably, from the Persian empire, which was now under the leadership of Darius II, successor to Artaxerxes. Athens had, since the peace made with Persia, provided support to a revolution against Persia in one of its own territories. This prompted the Persian empire, angered by Athens but not prepared for another all-out war with Greece, to provide some support to Sparta in its war against Persia's primary Greek enemy.
Despite these many obstacles, Athens remained prepared for battle. Its fleet, though dangerously depleted, was still enough to keep it from being overtaken, and its military reserves were enough to sustain it for some time. However, the military reality was that Sparta, with its nearly undefeatable land army, ships from the Peloponnesian League and Syracuse and support and funding from Darius II, was no longer vulnerable to defeat by Athens. In 411 BCE, the internal strife of Athens over the war grew so great that the Athenian democracy, a political idea to which the very cultural identity of Athens was attached, was overthrown in favor of the oligarchical form of government more typical of Sparta. At one point, a small group among the new rulers, 400 members of the Athenian aristocracy, even offered to betray Athens to a full Spartan invasion. This plot, however, did not manage to come together, as even under its new government, Athens was greatly opposed to the idea of Spartan rule.
At the same time, however, there had been a massive military rift in Athens, as is all too common throughout history when regimes change during a period of war. The Athenian fleet, though still dead-set against Sparta, refused to acknowledge the new regime and instead continued the war with Sparta from its base on the island of Samos, though its ability to function on its own against the Peloponnesian alliance was limited. In the battle of Syme in the same year, the fleet was dealt a loss at the hands of a portion of the fleet that had been assembled by Sparta, but the Athenian navy would survive the confrontation with only acceptable losses. In two further battles that followed, those at Cynossema and at Cyzicus, the latter in 410 BCE, the Athenian fleet was much more successful, managing to score decisive victories against Sparta in the Aegean Sea.
Following this series of naval engagements that had put great pressure on both sides to bring the war to a conclusion, the Spartans made a proposal of peace to Athens that was refused, despite generous terms that would have returned Attica to Athenian control and resulted in the release of all captives on both sides. This peace offer is something of a strange one, as it is not known why Sparta, still by far the more dominant state in the war to that point, would have offered such generous terms, nor why Athens would have refused them given its already strained military position. The latter mystery is, in part, explained by the influence of a major Athenian politician named Cleophon, who had opposed peace with Sparta at every possible turn. Why, however, Athens would have allowed Cleophon to have his way in this matter, is something that is much less clear.
The next several years of the war, between 410 and 406 BCE, were a time of stalemate between the two powerful city-states. On the one hand, Athens, though wounded, won impressive victories against their enemies, particularly in the taking by force of Byzantium in 408 BCE. Despite the Athenian military's acquittal of itself in the field, however, Sparta still held the upper hand by virtue of its superior land force and the massive alliance that it had formed to support itself in the war.
The final push that Sparta needed to attain victory in the war would come in the person of a capable general by the name of Lysander. Though a full Spartan citizen, Lysander was a man of poor birth who was not among the Spartan elite, but worked his way up through the ranks to become a commander. Lysander is among the most prominent examples of the strange form of egalitarianism that existed within the superstructure of the all-pervading Spartan state, as few ancient societies would have so easily accommodated such a meteoric rise from common roots, even through military prowess. Lysander was also, though a hoplite by his training, a naval commander of great ability. The latter trait of his military ability became apparent at the Battle of Notium in 406 BCE, where Lysander was able to break an Athenian blockade that had kept Spartan ships trapped at Ephesus.
This victory was followed up by the larger and more important Battle of Aegospotami the following year. Lysander had become friends with Darius II's son, Cyrus, and used this diplomatic advantage to press Persia for the funding necessary to build the Spartan fleet anew. Earlier the same year, the Spartan fleet had been all but destroyed in the Battle of Arginusae, a major Athenian victory. A Spartan victory at sea was needed, and Lysander had demonstrated at Notium that he was the Spartan commander who was best equipped to deliver that victory. Setting out with the new fleet that he had assembled, Lysander began a series of raids throughout the Aegean, forcing Athens to send its navy after him. The need, from the standpoint of Athens, to defeat Lysander would have been great. If the city-state lost its naval control over the seas surrounding Greece and particularly the regions close to itself, it would lose the war.
The naval struggle in the Aegean finally culminated in the Battle of Aegospotami, where Lysander's new Spartan fleet faced off against against the majority of the remaining Athenian navy under the command of a general named Conon. Having cut off Lysander in a harbor near Lampsacus, the Athenian fleet waited for the Spartan general to attack, preferring to fight a defensive action. Lysander's fleet stayed in the harbor for several days, but eventually came out to the Athenian ships to engage in a direct battle. The result was the most spectacular naval victory in the history of Sparta. In one battle, Lysander all but destroyed the Athenian fleet that had, until that point, been the dominant naval force of the Greek world. A handful of ships, commanded by Conon, escaped to friendly waters and relayed the news of the Spartan victory to Athens, but the strategic power of the Athenian fleet was gone. Little now stood between the successful Spartan commander and Athens itself.
In 404 BCE, Athens, militarily exhausted and economically on the verge of complete destruction, surrendered to Sparta and allowed the Peloponnesian city-state to impose a government favorable to itself on the city. The measures that Sparta took against Athens, however, were minimal, possibly because the two had fought together in the Greco-Persian wars. This pro-Spartan government, known as the Thirty Tyrants, would last little more than a year before being toppled by a revolt as the result of their own cruelty and oppression of Athens. The effect on the power balance of Greece, however, would be longer-lasting. Sparta was now by far the dominant power in Greece, no longer sharing the rough balance with Athens that had prevailed since the invasions of the Persian Empire.
With regards to the history of Sparta, the subjugation of Athens can easily be called the high point. Though it had been a military force to be reckoned with for most of its history (with the exception of a period of understandable weakness immediately following the earthquake of 464 BCE) and had held hegemonic power over much of Greece in the years before the Persian invasions, Sparta had never enjoyed direct control over so much of Greece as it would in the few years that followed the Peloponnesian War. As was common in Greek history, however, this dominance would not be lasting. Less than a decade after the end of the Peloponnesian War, Sparta would once again find itself embroiled in a great military conflict. This time, however, it would not be an outside conqueror or a city-state with which it had long been at odds. The next war would come from within the Peloponnesian League itself, from the long-standing allied city-state of Corinth.