In 406 the Vandals advanced from Pannonia travelling west along the Danube without much difficulty, but when they reached the Rhine, they met resistance from the Franks, who populated and controlled Romanized regions in northern Gaul. Twenty thousand Vandals, including Godigisel himself, died in the resulting battle, but then with the help of the Alans they managed to defeat the Franks, and on December 31, 406 the Vandals crossed the Rhine, probably while it was frozen, to invade Gaul, which they devastated terribly. Under Godigisel's son Gunderic, the Vandals plundered their way westward and southward through Aquitaine.