 The Theban force arrived late in 370 BC, and it was led by Epaminondas and Pelopidas, both at this time Boeotarchs.As they journeyed into Arcadia, the Thebans were joined by armed contingents from many of Sparta's former allies, swelling their forces to some 50–70,000 men.In Arcadia Epaminondas encouraged the Arcadians to form their proposed league, and to build the new city of Megalopolis (as a center of power opposed to Sparta).