Ahenobarbus was captured with his father, Lucius Domitius Ahenobarbus, at Corfinium in 49 BC, and was present at the Battle of Pharsalus in 48 BC, but did not take any further part in the war. He did not however return to Italy until 46 BC, when he was pardoned by Julius Caesar. He probably played no part in Caesar's assassination, although some writers claim that he was one of the conspirators. He followed Brutus into Macedonia after Caesar's death, and was condemned by the Lex Pedia in 43 BC as one of the murderers.