perhaps the most prominent example of the phalanx's evolution was the oblique advance, made famous in the battle of leuctra. there, the theban general epaminondas thinned out the right flank and centre of his phalanx, and deepened his left flank to an unheard-of 50 men deep. in doing so, epaminondas reversed the convention by which the right flank of the phalanx was strongest. this allowed the thebans to assault in strength the elite spartan troops on the right flank of the opposing phalanx. meanwhile, the centre and right flank of the theban line were echeloned back, from the opposing phalanx, keeping the weakened parts of the formation from being engaged. once the spartan right had been routed by the theban left, the remainder of the spartan line also broke. thus, by localising the attacking power of the hoplites, epaminondas was able to defeat an enemy previously thought invincible.