The Battle of Peonnum was fought about AD 660 between the West Saxons under Cenwalh and the Britons of what is now Somerset in England.
[2] Relief for the Britons came when Cenwalh was exiled to East Anglia after a squabble with Penda of Mercia.
[3] Some time after his return he renewed the attack on the British tribes and in 658 his army met the Britons for a climactic battle at Peonnum.
The Saxons were victorious, and Cenwalh advanced west through the Polden Hills to the River Parrett, annexing eastern and central Somerset.
[4] The border remained at the Parrett until 681–685, when Centwine of Wessex defeated King Cadwaladr of Gwynedd and his local allies, allowing them to occupy the rest of Somerset west and north to the Bristol Channel.