In 42 BC he commanded a fleet of fifty ships in the Ionian sea, and gained considerable success against the Second Triumvirate, completely defeating Gnaeus Domitius Calvinus on the day of the first battle of Philippi, as the latter attempted to sail out of Brundisium.
He became consul, according to agreement, in 32 BC, in which year the open rupture took place between Antony and Augustus.