Battle of Tegyra The Battle of Tegyra ( 375 BC ) ( also known as the Battle of Tegyrae ) was an ancient Greek battle between Theban and Spartan hoplite forces . In the battle , a Theban army under Pelopidas was challenged by a substantially larger Spartan force while retreating from an abortive attack on Orchomenus , but successfully attacked and routed the Spartans . The battle marked the first occasion in the historical record in which a Spartan force had been defeated by a numerically inferior enemy in a set battle ( as opposed to irregular warfare , employed by Iphicrates ) . Prelude . After an insurrection in 379 / 8 BC removed Spartan control over Thebes , the city set about reestablishing its control over the Boeotian League . Over several years of campaigning , the Thebans succeeded in driving Spartan garrisons out of every city in Boeotia but Orchomenus . In 376 BC , Pelopidas , learning that the Spartan garrison of Orchomenus had gone on an expedition to Locris , set out with the Sacred Band of Thebes and a small force of cavalry , intending to seize the city while it was unguarded . As the Thebans approached the city , however , they learned that a sizable force had been dispatched from Sparta to reinforce the Orchomenus ' garrison , and was approaching the city . Accordingly , Pelopidas retreated with his force , but before the Thebans could reach safety at Tegyra , they met the original Spartan garrison returning from Locris . Battle . The Theban force was heavily outnumbered by the Spartans opposite them . The Sacred Band numbered some 300 hoplites , while the Spartan garrison consisted of two companies , meaning that the Spartan force contained between 1 , 000 and 1 , 800 hoplites . Plutarch reports that one Theban soldier , upon seeing the enemy force , said to Pelopidas " We are fallen into our enemies ' hands , " to which Pelopidas replied " And why not they into ours ? " Pelopidas then ordered the Theban cavalry to charge while the infantry formed up into an abnormally dense formation . When the two phalanxes came together , the compact Theban formation broke through the Spartan line at the point of contact , then turned to attack the vulnerable flanks of the Spartans to either side . The Spartan force broke and fled , although the Theban pursuit was limited by the proximity of Orchomenus . Significance . The Theban victory at Tegyra had little immediate military significance , beyond the survival of Pelopidas ' s force ; the Spartan force , once regrouped within Orchomenus , was far too formidable for Pelopidas to press his advantage . Despite this fact , the victory was a symbolically significant event for both sides . Diodorus Siculus records that the victory at Tegyra marked the first time the Thebans had erected a trophy of victory over a Spartan force — for while the Thebans had defeated the Spartans before , these victories had generally been in much smaller skirmishes . For the Spartans , on the other hand , their defeat at Tegyra marked the first occasion on which one of their formations had been defeated by a force of equal or lesser size in set battle . For these reasons , Plutarch saw in Pelopidas ' victory at Tegyra a " prelude to Leuctra " , with the limited victory in 375 anticipating the day 4 years later when a similarly outnumbered Theban phalanx would deal Sparta a blow from which it would never recover .