Before the Viking incursions that started in the late 8th century, the area of modern Scotland was divided between four main cultural and linguistic groupings: the Gaels of Dál Riata, the Britons, the ngles and the Picts, though identities and political groupings were in a constant state of flux and could often change among and between them. The Gaels occupied the west of modern Scotland north of the Firth of Clyde and were part of a Gaelic linguistic and cultural zone that included Ireland, from which it was separated only by the short sea crossing of the North Channel. To the south a number of British kingdoms had developed in the aftermath of the withdrawal of the Roman Empire, including Alt Clut in the basin of the River Clyde, Rheged to the south around the Solway Firth, and the Gododdin to the east around Edinburgh. In the south east Bernicia had been established as a Germanic-speaking Anglian kingdom based around Bamburgh in modern North East England in the mid 6th century, and by 638 had captured Edinburgh and gained much of the territory of the Goddodin around Lothian. The Picts largely occupied the lands in the east of modern Scotland north of the Forth, and were originally a diverse group of peoples defined at least in part by never having been Romano-British.
