Kingdom of Strathclyde

Strathclyde, called Ystrad Clud in Welsh and known in its early centuries as the kingdom of Alt Clut, was a Brittonic realm in northern Britain that emerged after the collapse of Roman rule. Its original centre was Dumbarton Rock on the Clyde, a fortress controlling the river route into the Highlands; its people spoke Cumbric, a language closely related to Old Welsh, and traced their origins to the Damnonii recorded by Ptolemy. The kingdom's early kings are known mainly from Irish and Welsh sources: Ceretic, the recipient of a letter from Saint Patrick, and Rhydderch Hael, a contemporary of Columba and of Aedan of Dal Riata. In 870 a Viking army from Dublin besieged Dumbarton for four months, destroyed the citadel and carried off a great host of captives; afterwards the royal centre seems to have shifted to Govan, and the enlarged realm became known as Strathclyde or Cumbria. At its height in the tenth century it stretched from Loch Lomond south to the River Eamont near Penrith, and its kings fought and allied with the Scots of Alba, the Northumbrians and the Vikings. Scots influence grew after the tenth century, and the kingdom was absorbed into the emerging Kingdom of Scotland in the eleventh century, its name surviving in the later title of Prince of Cumbria.