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 or