Complex sentence: Menander (in Greek Mενανδρoς; lived 4th century BC) was an officer in the service of Alexander the Great, one of those called "etairoi", but who held the command of a body of mercenaries.
Split into simpler sentences: Menander (in Greek Mενανδρoς; lived 4th century BC) was an officer in the service of Alexander the Great. He was one of those called "etairoi", but he held the command of a body of mercenaries.