Answer:
The end of the Peloponnesian War did not bring the promised “…beginning of freedom for all of Greece.”[1] Instead, Sparta provoked a series of wars which rearranged the system of alliances which had helped them win the long war against Athens. A peace conference between Sparta and Thebes in 371 ended badly and the Spartans promptly marched upon Thebes with an army of nine thousand hoplites and one thousand cavalry. Opposing them were six thousand Theban and allied hoplites and one thousand cavalry.[2]
Over generations, the Thebans had been increasing the depth of their phalanx, generally given pride of place on the right wing of coalition armies, from the traditional eight men, to sixteen, then twenty-five and even thirty-five ranks. As the Spartan and Theban armies maneuvered toward the plain of Leuctra, the brilliant Theban general Epaminondas devised a new tactic which would use the deep phalanx to destroy the myth of Spartan superiority.
Over the generations, the citizens of Thebes had developed a reputation as tough, unyielding fighters. Epaminondas had witnessed the power of the deep Theban phalanx at previous battles, and increased the depth of the phalanx to fifty ranks, but only eighty files wide. But Epaminondas’ true innovation was to position the deep Theban column not on the right, where it would have clashed with the Spartan’s weaker allies, but on the left, where it would attack the main phalanx of the Spartan “Peers” led by King Cleombrotus, arranged only twelve ranks deep. In other words, Epaminondas was concentrating his fighting power at the critical point in the evenly-spaced, less concentrated Spartan phalanx. Finally, he arranged the Theban’s allies on his right would advance “in echelon”, each poleis’ phalanx staying slightly to the rear of that to its left, so that the allied right would protect the Theban’s flank, but not initially engage with the enemy (see Leuctra map – ‘Initial Situation’). When asked why he positioned the Theban phalanx opposite the Spartan king, Epaminondas stated he would “crush…the head of the serpent”.[3]
