Ystrad Clud (Strathclyde) is the river valley (Welsh ystrad, Gaelic srath) of the Clyde, now in south-central Scotland (ALBA). This term was used as the name of a kingdom recorded from 872, also known as Cumbria from the mid-10th century. Cludwys (people of the Clyde) occurs in the 10th-century political prophecy ARMES PRYDEIN. Strathclyde has often also been used by modern writers as a shorthand for the kingdom that preceded the destruction of the fortress of Al Clud (Dumbarton Rock) by Vikings in 870. That kingdom centred on the power base of Dumbarton Rock, whose kings were normally referred to in contemporary ANNALS as kings of Al Clud (Gaelic Ail Cluaithe), or simply kings of the Britons. Although these earlier kings may well have controlled much, if not all, of Clydesdale (modern Lanarkshire), it seems as if that polity ended with the events of 870 and Strathclyde marked the start of a new polity. If we take later medieval territorial jurisdictions as a guide, the kingdom based on Dumbarton Rock may have most easily controlled the Lennox (essentially modern Dumbartonshire) and the southern side of the Firth of Clyde (modern Renfrewshire), as well as Clydesdale itself, but there is little hard evidence to support this supposition.
The kingdom on the Clyde at Dumbarton was the most persistent of the northern British kingdoms in the early Middle Ages. Its king, Rhydderch Hael, appears in the 9th-century text Historia Brittonum, in an account set in the late 6th century, as one of the kings allied against the power of Bernicia (Brynaich). Rhydderch can also be dated to this period by his appearance in an anecdote in Vita Columbae (Life of CoLUM CiLLE, t597), written c. 700 by Adomnan.
A mid-7th century victory at Srath Caruin (now Strathcarron), under Eugein map Beli, appears to have freed parts of the Dumbarton kingdom from the dominance of Dal Riata, with whom there was relatively constant strife. There are some question marks over the relationship between Northumbria and northern British kingdoms in the later 7th century; certainly the victory at Nechtanesmere by Eugein’s brother, the Pictish king Bruide mac Bili, in 685 appears to have freed the northern Britons from Northumbrian tribute or overlordship.
Dumbarton kings are again prominent in the first half of the 8th century, but in 756 the kings were forced to submit to the allied powers of the Pictish king Unuist son of Uurguist and the Northumbrian Ecgberht. Its kings disappear from record for nearly a century. Both Viking incursions and succession disputes weakened the Pictish kingdom in the 840s, allowing Dumbarton to emerge from its shadow.
The first references to the kingdom of Ystrad Clud occur in the aftermath of the siege and sacking of Dumbarton Rock. The new kingdom had expanded as far south as the river Eamont by the mid-10th century. New people - and kingdom-names came about to describe a polity no longer limited to Ystrad Clud itself: Welsh Cymry, Latin Cumbrenses and Cumbria, Old English Cumbras and Cumbraland.
The kingdom certainly lasted until 1018, when its king Owain ap Dyfnwal died fighting alongside the king of Alba, Mael Coluim mac Cinaeda. Nevertheless, the description of Siward, earl of Northumbria, waging war on Mac Bethad mac Findlaich and trying to place on the throne of Alba one ‘Malcolm, son of the king of the Cumbrians’ in 1054/5 reminds us that the kingship may have lasted somewhat longer—though Malcolm may have been Owain’s son. It has long been thought that this Malcolm was the future Mael Coluim (III) mac Donnchada, and that Donnchad was therefore ‘king of the Cumbrians’ before he became king of Alba, but this equation is now thought to be highly unsound.
David I could address the inhabitants of land around Carlisle as Cumbrenses, and speak of Ranulf le Meschin of Carlisle as holding power in ‘his land of Cumberland’. David moreover describes himself in his Inquest into the properties of the cathedral of Glasgow (Glaschu) as Cumbrensis regionis princeps, and this Inquest initiated a reclamation by the Glasgow diocese of its Cumbrian and ‘Welsh’ identity in the face of pressure from York, which claimed Glasgow to be its subordinate. The diocese’s identification of itself with the former kingdom of Cumbria preserved the memory of that kingdom long after its political existence was at an end. By this point, Ystrad Clud itself, Clydesdale, had been settled by land grants to many of David’s trusted retainers, men largely from Flanders, Brittany, Normandy, and England. Thus the articulation of a Cumbrian identity for the region happened simultaneously with its permanent linguistic and cultural transformation.
Thomas Owen Clancy