Battle of Maserfield
The battle of Maserfield (or Maserfeld) was fought August 5, 642, between the Anglo-Saxon kings Oswald of Bernicia and Penda of Mercia, ending in Oswald's defeat, death, and dismemberment.Since the death of Oswald's uncle Edwin of Northumbria at Hatfield Chase in 633, Mercia under Penda had been dominant in the north of England. Oswald had already avenged Edwin's death by defeating the Britons at Heavenfield, and now purposed to do the same to Penda, bringing his army to Maserfield, now Oswestry ("Oswald's Tree") in Shropshire, near the Welsh border.
For his part, Penda gathered with his Welsh allies, drawn from realms that included Powys, Gwynedd, and Pengwern.
For the battle, no details are known beyond the outcome; Penda defeated and killed Oswald. Oswald's body was cut into pieces, and his head and arms mounted on poles. Penda being pagan and Oswald Christian, this made Oswald a martyr, and Bede reports many miracles attributed to the various body parts revered as relics.
Maserfield cemented Penda's ascendance over the Northumbrians, which lasted until his death at the Battle of Winwaed thirteen years later.