Epaminondas (410-362 BC) was a Theban general and statesman who was responsible for a series of battlefield victories that smashed the power of Sparta, ending a short period of Spartan dominance in Greece.
Epaminondas was born into an aristocratic Theban family. He was educated by Lysis of Tarentum, a Greek philosopher and member of the Pythagorean school who fled into exile from Sicily in around 390 BC.
In 382 a Spartan army was passing Thebes during an expedition to northern Greece. The Spartans decided to seize the Cadmea (the citadel of Thebes) and installed a dictatorial government. The previous Theban leaders, including Pelopidas, were forced into exile, while Epaminondas, who at this time had no political record, remained in Thebes.
In December 379 Pelopidas returned from exile and led a revolt against the Spartans. Epaminondas was one of the leaders of a popular uprising in Thebes that helped the returning exiles. The Spartans were besieged in the Cadmea and forced to surrender. This triggered a general war (Theban-Spartan War, 379-371), which saw Thebes and Athens defeat a series of Spartan attempts to regain control in Boeotia. The Spartans suffered a series of defeats outside Thebes, and Epaminondas presumably fought in some of these battles.
In 371 Epaminondas was boeotarch, one of the five magistrates of the Theban federation. He represented the city at a peace conference which ended the wider conflict, but the status of the Boeotian League caused a problem. Athens and Sparta wanted each Boeotian city to be treated separately, while Epaminondas wanted them to be represented by the League. Neither side was willing to budge, and the peace was eventually signed without Thebes.
In July 371 Cleombrotus of Sparta invaded Boeotia from the west at the head of 10,000 men. This was the moment when Epaminondas emerged as a great military leader, inflicting a major defeat on the Spartans at the battle of Leuctra (371 BC.). Epaminondas adopted a novel tactical formation during the battle. The normal Greek formation was to have a fairly even line of hoplites, with the commander on the right. Epaminondas decided to counter the Spartans by massing most of his hoplites on his left wing, and advanced with the left wing ahead of the centre and right of the army. This strengthened Theban left clashed with the Spartan right, and routed it. The defeated Spartan right broke up the formation of their centre, and the army collapsed. Cleombrotus was killed in the battle and the Spartans were forced to acknowledge defeat. The Spartans may have lost as many as 1,000 men, an almost unsupportable loss for the warrior state, which was always short of full citizens.
Over the next decade Epaminondas led four expeditions into the Peloponnese, effectively destroying Spartan power. The first took place in the winter of 370-369 and saw the Thebans reach the Eurotas valley, within sight of Sparta. The helots rebelled, and Epaminondas was able to restore the independence of Messenia, which had been conquered by Sparta nearly three hundred years earlier. This greatly reduced the agricultural base of the Spartan economy, which had depended on the helots since the 8th century BC. During the same expedition he encouraged the new Arcadian League to found a capital city at Megalopolis.
Typically for the Greek states the Theban response to these successes was to impeach Epaminondas for retaining power beyond his official year of office. He was acquitted, but this demonstrated the unstable nature of Greek politics.
In 369-368 he led a second expedition into the Peloponnese, once again increasing Theban power., although by this point Athens was concerned about the rise of Theban power, and helped to repel a Theban attack on Corinth.
In 367 Pelopidas was captured by Alexander, tyrant of Pherae in Tessa. Epaminondas joined the army sent to rescue him as a common soldier, but was soon promoted to command the army when it ran into trouble. He was then re-elected at boeotarch and freed Pelopidas in a second campaign. The same year also saw the Persians decide to side with Thebes in the struggle. Partly as a result of this the Athenians decided to form an alliance with Sparta, turning against their former allies.
In 366 Epaminondas led a third campaign into the Peloponnese. He gained more promises of support from local cities, and decided to leave the Sparta-established oligarchies in power. This policy was rejected back in Thebes, in favour of installing democracies in the cities. The exiled oligarchs soon returned to power in most of the cities, and Achaea became a Spartan ally.
In 364 Pelopidas was killed in battle at Cynoscephalae, another clash in Thessaly. The Thebans had been called to Thessaly to oppose Alexander of Pherae. Pelopidas led an army into Thessaly, but this was disbanded after a solar eclipse. Pelopidas continued with the campaign anyway, and actually defeated Alexander at Cynoscephalae, but was killed in the victory. This left Epaminondas as the main remaining Theban military leader.
In 364-363 Epaminondas led a Theban naval expedition to the Bosporus, where he was able to convince several Athenian possessions to rebel. The most important of these was Byzantium, but otherwise the costly expedition didn’t achieve much and we don't hear of the Theben fleet taking part in any further major expeditions.
In 362 a civil war broke out in the Arcadian League. Epaminondas led a fourth campaign into the Peloponnese. This campaign ended at the battle of Mantineia (4 July 362), a large clash between two allied armies. Epaminondas commanded a force of Thebans, Messenians, Argives and southern Argives. The Spartans had their own troops as well as forces from Athens, Elis and northern Arcadia. Epaminondas adopted a similar plan to Leuctra, with a strongly reinforced flank, using trickery to conceal his intentions. He won a similar victory, but he was killed towards the end of the battle. His death took all of the impetus out of Theban policy, and effectively marked the end of the decade long period of Theban ascendancy.
At some point early in his life the future Philip II of Macedon spend some time in Thebes, probably starting in around 370-369 BC, when he was about ten, although the ancient sources disagree on the reason for this visit, the nature of it (hostage or for his own protection) and the end date - before or after the death of his brother s III. Philip was said to have studied the military achievements of Epaminondas and Pelopidas, and as he may have been as old as seventeen when he returned home, this is entirely plausible.