In the 1st century BC, the Sequani tribe (the most "Gaulish of Gauls" according to historian Henri Martin), which was centered around Besançon, settled in Sundgau. From 70 BC, they waged perpetual warfare with their neighbours, the Aedui, calling upon German mercenaries, led by Ariovistus. When the conflict finished, the Germans settled into the region, and the Sequani, to remove them appealed to the Romans. Julius Caesar defeated Ariovistus in 58 BC near Cernay, and a long domination by the Romans commenced. This ended suddenly in 405, when the Alamani crossed the Rhine and occupied Sundgau. They, in turn, were followed by the Franks following their victory at the Battle of Tolbiac in 496. Sundgau was incorporated into the kingdom of Austrasia and Christianity was introduced under the Merovingians.