Battle of Hatfield Chase

The Battle of Hatfield Chase was fought on 12 October 633 at Hatfield Chase near Doncaster . It pitted the Northumbrians against an alliance of Gwynedd and Mercia. The Northumbrians were led by Edwin and the Gwynedd-Mercian alliance was led by Cadwallon ap Cadfan and Penda. The site was a marshy area about 8 miles northeast of Doncaster on the south bank of the River Don. It was a decisive victory for Gwynedd and the Mercians: Edwin was killed and his army defeated, leading to the temporary collapse of Northumbria.
Edwin, the most powerful ruler in Britain at the time, had seemingly defeated Cadwallon a few years before the battle. Bede refers to Edwin establishing his rule over what he called the Mevanian islands, one of which was Anglesey, and another source refers to Cadwallon being besieged on the island of Priestholm , which is off the coast of Anglesey. Later, Cadwallon defeated and drove the Northumbrians from his territories and then allied with Penda . Penda's status in Mercia at this time is uncertain—Bede suggests he was not yet king, but became king soon after Hatfield; the Anglo-Saxon Chronicle, however, says that he became king in 626.

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