Hannibal needed to cross the Pyrenees, the Alps, and many important rivers in the region. starting in the spring of 218 BC, he fought his way to the Pyrenees. He made peace deals with the Gaulic tribal leaders and reached the Rhône River. Arriving at the Rhône in September, Hannibal's army numbered 38,000 infantry, 8,000 horsemen, and thirty-seven war elephants.