460 BC - 445 BC
Prior to the Greco-Persian Wars, the hegemony of Sparta over the Greek mainland was largely uncontested. When the Persian threat presented itself, the other city-states looked to Sparta as the obvious choice to lead the defense. But they began to cede that assumed leadership early. It was Athens who won the Battle of Marathon, the first major conflict, with Sparta showing up afterward due to their observing the Olympic Truce.
This reached a pinnacle when the Athenian led navy routed the Persian fleet. After the final defeat of the Persian land forces at the Battle of Plataea and the siege of Byzantium, Sparta's part of the war came to an end and their general, was called home. This unofficially gave leadership of the Greek alliance to Athens, who began to lead the allies in a counter-attack on the coasts of Asia Minor. These victories set the stage for the Athenian dominated Delian League, a voluntary alliance meant to continue the fight against the ever-formidable Persian Empire.
However, it didn't take long for Athens to assert its dominance, and the League eventually become known as the Athenian Empire. And Athens waxed fat and wealthy.
And Sparta and it's allies, known as the Peloponnesian League, looked on in concern and envy.
Two giant bows had arrows knocked, poised for conflict, the solidarity brought by the Persian invasion forgotten. Technically during this time period, they were allies. But an act of nature would help bring the tension to the forefront, and show that an influential segment of the Spartan leadership wanted war with Athens.
Strangely, the event that many mark as the beginning of open hostility between Athens and Sparta is an earthquake. During the Thasian rebellian, where the city-state of Thasos attempted to leave the Delian League over a dispute, this earthquake struck the Laconia mainland, killing many of the Spartan warrior citizens and cracking their sphere of influence.
The helots, perpetual slaves of Sparta, used this opportunity to revolt. And they could not be subdued easily.
Sparta sent out word for help from their allies to break the rebellion, and Athens sent an army of 4,000 men under the leadership of Cimon. For reasons that can only be guessed at, Sparta rebuked the offer of help and sent Cimon home in embarrassment.
In response to the insult, since they were the only ally the Sparta refused help from, Athens began forming alliances at strategic and contestable points, including one with Argos, Sparta's long-time enemy. Others included Megara and Thessaly.
These alliances, coupled with helping settle exiled helots somewhere, eventually resulted in war with northern members of the Peloponnesian League, such as Corinth, beginning in 460 BC. Sparta is noticeably absent during the early years, probably because they were still weakened from the earthquake and preoccupied with the subsequent slave revolt.
At one point, Athens actually controlled most of Central Greece.
Battle of Tanagra (457 BC)
- Battle of Oenophyta (457 BC)
- Battle of Coronea (447 BC)
The Conflict (temporarily) Ends:
Around the beginning of the war, Athens had committed close to 200 ships of the League to help Egypt in it's revolt against Persia. Beginning with several fronts and resources spread thin did not exactly bode well for an ultimate Athenian victory.
The Egyptian revolt was eventually crushed, shaking Athens control of the Aegean Sea, and forcing them to rethink their strategy. This, coupled with other setbacks, and their inability to secure any long-term gains on land, encouraged them to sue for peace.
This first peace was broken, of course, with Sparta's refusal to attend the Congress called for by Pericles, followed by the revolt of Boeotia. The truce is extended 30 years, Megara is returned to the Peloponnesian League, and both sides agree to respect the alliances of the other.
The so-called "Thirty Years Peace" would last less than half of that time. Greece remained bipolar in structure, with all the enmity still festering. Athens and Sparta would spar again.