The main struggle (58–50 BC) against the Romans came against Julius Caesar under Vercingetorix at Battle of Gergovia (a city of the Arverni) and at the Battle of Alesia (a city of the Mandubii). The Gaulish commander was captured at the siege of Alesia and the war ended. Caesar seized the remainder of Gaul, justifying his conquest by playing on Roman memories of savage attacks over the Alps by Celts and Germans. Italy was now to be defended from the Rhine.