In 31 BC, it fought in the Battle of Actium against Mark Antony. Although Actium was a battle at sea, the legion was able to board enemy ships that had been hooked close by means of an iron grapnel known as the Corvus. Its key participation in this battle is probably the reason that the legion also used a trireme as one of its symbols. Actium marked the end of the civil war and the rise to power of Octavian, who was proclaimed Augustus some years later.