 Certainly, he served with the Theban armies in the defence of Boeotia in the 370s, and, by 371 BC, he had become a Boeotarch.It seems safe to assume, given their close friendship, and their close collaboration after 371 BC, that Epaminondas and Pelopidas also collaborated closely on Theban policy in the period 378–371 BC.The years following the Theban coup had seen desultory fighting between Sparta and Thebes, with Athens also drawn into the conflict.