Nicias was a moderate Athenian politician and rival to Cleon and later Alcibiades. He successfully negotiated a temporary peace treaty with Sparta in 421 BC.
Despite opposing the Sicilian Expedition, he was appointed as one of its commanders. His indecision and superstition contributed to the complete destruction of the Athenian forces.
He was captured and executed by the Syracusans after the failure of the expedition.