In 717, Charles returned to Neustria with an army and confirmed his supremacy with a victory at Vincy, near Cambrai. He chased the fleeing king and mayor to Paris before turning back to deal with Plectrude and Cologne. On succeeding there, he proclaimed Chlothar IV king of Austrasia in opposition to Chilperic. In 718, Chilperic, in response, allied with Odo the Great, the duke of Aquitaine who had made himself independent during the contests in 715, but he was again defeated by Charles, at Soissons. The king fled with his ducal ally to the land south of the Loire and Ragenfrid fled to Angers. Soon Chlothar IV died. Odo then gave up on Chilperic and, in exchange for Charles recognising Chilperic's kingship over all the Franks, the king surrendered his political power to Charles, whom he recognized as Mayor over all the kingdoms (718).