The Battle of Penn Hill was fought in AD 665 between a British and an Anglo-Saxon coalition at Penn Hill in northern Dumnonia, the precise location of which is unknown. It resulted in a decisive British victory, and reversed the Saxon expansion westwards across Albion. Germanic migrants, mainly from the Angle, Saxon and Jutish tribes, began arriving on the east coast of Albion in the mid-5th century, during the chaos following the Roman withdrawal from the provinces of Britannia. They quickly pe