Strathclyde was a Brittonic kingdom in northern Britain during the Middle Ages. It comprised parts of what is now southern Scotland and North West England, a region the Welsh tribes referred to as Yr Hen Ogledd. At its greatest extent in the 10th century, it stretched from Loch Lomond to the River Eamont at Penrith. Strathclyde seems to have been annexed by the Goidelic-speaking Kingdom of Alba in the 11th century, becoming part of the emerging Kingdom of Scotland.
Looking north at Dumbarton Rock, the chief fort of Strathclyde from the 6th century to 870. The fort of Alt Clut was on the right-hand summit.
Dumbarton seen across the estuary of the River Clyde at low tide.
Clach nam Breatann, Glen Falloch, perhaps the northern edge of Strathclyde
Image: Yr.Hen.Ogledd.550.650.Koch
A strath is a large valley, typically a river valley that is wide and shallow.
Strath Carnaig river