Gorgidas was the first known Theban military leader of of troop of select soldiers annihilated in what battle?
Gorgidas: Gorgidas (Ancient Greek: Γοργίδας) was the first known Theban military leader of the Sacred Band of Thebes around 378 BC. Sacred Band of Thebes:  It was annihilated by Philip II of Macedon in the Battle of Chaeronea in 338 BC.
the Battle of Chaeronea