Kingdom of Strathclyde

Strathclyde, also known as Alt Clud in its early days, was a Brittonic kingdom in northern Britain during the Middle Ages. It encompassed parts of what are now southern Scotland and northwest England, referred to by Welsh tribes as Yr Hen Ogledd ("the Old North"). At its greatest extent in the 10th century, Strathclyde stretched from Loch Lomond to the River Eamont at Penrith. The kingdom was annexed by the Goidelic-speaking Kingdom of Alba in the 11th century, becoming part of the emerging Kingdom of Scotland.

The kingdom's early capital was Dumbarton Rock, and it was known as the Kingdom of Alt Clud. It likely emerged during Britain's post-Roman period and may have been founded by the Damnonii people. After a Viking sack of Dumbarton in 870, the capital moved to Govan, and the kingdom became known as Strathclyde. It expanded south into the former lands of Rheged. The Anglo-Saxons called this enlarged kingdom Cumbraland. The language of Strathclyde, known as Cumbric, was closely related to Old Welsh. Its inhabitants, the Cumbrians, experienced some Viking or Norse-Gael settlement, though less than in neighboring Galloway.

The Kingdom of Alt Clud saw increased mention in sources after 600 CE. At the beginning of the 7th century, Áedán mac Gabráin of Dál Riata was a dominant king in northern Britain, but his power waned after a defeat by Æthelfrith of Bernicia at the Battle of Degsastan around 604. In 642, the Britons of Alt Clut, led by Eugein son of Beli, defeated Dál Riata at Strathcarron, killing Domnall Brecc, a grandson of Áedán.

Alt Clut's involvement in regional conflicts continued, with battles against Dál Riata reported in the 8th century. The Pictish king Óengus I campaigned against Alt Clut multiple times, with mixed results. In 756, Óengus and Eadberht of Northumbria besieged Dumbarton Rock, extracting a submission from Dumnagual, the likely king at the time. Little is known about Alt Clut between the 8th and 9th centuries. The "burning" of Alt Clut in 780, the circumstances of which are unclear, marks one of the few mentions of the kingdom. In 849, men from Alt Clut burned Dunblane, possibly during the reign of Artgal.The Kingdom of Strathclyde's independence ended when it was annexed by the Kingdom of Alba in the 11th century, contributing to the formation of the Kingdom of Scotland.