The prevailing view of the period of Viking rule in Brittany is that Scandinavians came from outside, attempted to subjugate the inhabitants, and were eventually driven out by Bretons. This paper examines political language in Brittany during this period and argues instead that the period of Northman rule in the peninsula was the result of vicious factional politics. The development of regalian, Carolingian-influenced languages of legitimacy in the late ninth century is discussed and compared with alternatives to determine why Northman ideologies emerged as salient. The ‘Viking occupation’ is thus reinterpreted as arising out of the internal dynamics of the peninsula rather than being an alien intrusion.