The full statement of received opinion has been that a mixed band of Vandals, Alans and Suebi crossed the Rhine at Mainz on December 31, 406, and began to ravage Gaul. Several written accounts document the crossing, supplemented by the time line of Prosper of Aquitaine, which gives a firm date of 31 December 406. Zosimus' New History (vi.3.1) imputes the usurpation of Marcus in Britannia to a reaction to the presence of barbarians in Gaul in 406; from a fragment of Olympiodorus, the acclamation as Emperor of Marcus, the first of the Romano-Britannic usurpers, took place that same summer.