In the war against the Neustrians, at the battle of Soissons in 719, Charles had encountered in their ranks Eudes or Eudon, Duke of Aquitania and Vasconia, that beautiful portion of Southern Gaul situated between the Pyrenees, the Ocean, the Garonne, and the Rhone, who had been for a long time trying to shake off the dominion of the barbarians, Visigoths or Franks. At the death of Pepin of Heristal, the Neustrians had drawn into alliance with them, for their war against the Austrasians, this Duke Elides, to whom they gave, as it appears, the title of king. After their common defeat at Soissons, the Aquitanian prince withdrew precipitately into his own country, taking with him the sluggard king of the Neustrians, Chilperic II. Charles pursued him to the Loire, and sent word to him, a few months afterwards, that he would enter into friendship with him if he would deliver up Chilperic and his treasures; otherwise he would invade and ravage Aquitania. Eudes delivered up Chilperic and his treasures; and Charles, satisfied with having in his power this Merovingian phantom, treated him generously, kept up his royal rank, and at his death, which happened soon afterwards, replaced him by another phantom of the same line, Theodoric or Thierry IV.; whom he dragged from the abbey of Chelles, founded by Queen St. Bathilde, wife of Clovis II., and who for seventeen years bore the title of king, whilst Charles Martel was ruling gloriously, and was, perhaps, the savior of the Frankish dominions. When he contracted his alliance with the Duke of Aquitania, Charles Martel did not know against what enemies and perils he would soon have to struggle.