The Battle of Dyrham / Deorham is an event recorded in the Anglo-Saxon Chronicle for the year AD 577:
Here the Saxons under Cuthwine and Ceawlin fought against the Britons, and they killed 3 kings, Coinmail, Condidan and Farinmail, in the place which is called Deorham, and took 3 cities: Gloucester and Cirencester and Bath
Deorham is usually associated with the modern village of Dyrham in Gloucestershire.
The battle has often been interpreted as a significant, defining event in the history of Britain. It has been seen as a strategic blow separating the south-western peninsula's ‘Dumnonia’ from Wales.
It has also been argued as a major event in the ethnic and linguistic landscape of early medieval Britain and as important evidence for the continuity of Romano-British urban life into the sixth century in the West Country.