Battle of Maserfield
There is no record of what led to this battle or why this place. As a pagan, Penda would not have been happy over Oswald bringing monks from Iona to Lindisfarne, further expanding Christianity in the north. The conquest of the Gododdin at  Din Eidyn  (Edinburgh) in 638 removed the last stronghold of the Britons in the north. Domnall Brecc, King of Dal Riata defeated them and was a close ally of Oswald. Northumbrians may have been there also. It would have angered the Welsh, Britons themselves, against Oswald. In 642 the armies of Northumbria and Mercia (with his Welsh allies) met at a place called  Maserfield (probably in Shropshire). Oswald was killed in the battle. For a year after the battle his head and hands were fastened to stakes. Oswald's brother Oswiu finally recovered Oswald's body. Oswiu succeeded Oswald as king of Northumbria.