According to established models of language contact, communication between incoming settlers and indigenous populations leads to the survival of place-names, whose role as labels means that they can easily be transferred between groups of speakers without understanding of semantic content. The paucity of pre-Norse place-names in the Northern and Western Isles of Scotland, like the paucity of pre-Anglo-Saxon place-names in southern Britain, has therefore been taken to reflect a lack of continuity of settlement that is at odds with the archaeological and historical record. This paper argues that, during the Anglo-Saxon and Viking Ages, place-names served functional purposes, where semantic content was important. This may account for the loss of place-names that were semantically opaque to incoming settlers.