Battle of Alclud Ford
580 CE.
Shown on the map at 55.937°, -4.562°.
The Battle of Alclud Ford took place between the post-Roman Celtic Britons of Rheged and the Anglo-Saxon Kingdom of Bernicia around c. 580CE. The fighting may have taken place at an unknown ford near Alt Clut, the original name for Dumbarton Rock, which may also be used for the entire ancient Kingdom of Strathclyde. The battle is recorded in two poems in the Book of Taliesin.
Text from the Wikipedia article Battle of Alclud Ford, licensed CC BY-SA 4.0.