Gaulish in Western Europe was supplanted by Vulgar Latinfor the early development of Vulgar Latin (the conventional term for what could more adequately be named "spoken Latin") see Mohl, Introduction à la chronologie du latin vulgaire (1899) and Wagner, Introduction à la linguistique française, avec supplément bibliographique (1965), p. 41 for a bibliography. and various Germanic languages from around the 5th century AD onward. It is thought to have become extinct some time around the late 6th century.
