Brittonic languages
Roman historians, including Tacitus and Cassius Dio, referred to the territory north of the River Forth as “Caledonia,” and described it as inhabited by the Maeatae and the Caledonians (). Other ancient authors, however, used the adjective "Caledonian" more generally to describe anything pertaining to inland or northern Britain. The name is probably derived from a word in one of the Gallo-Brittonic languages.