Ecgfrith (c. 645–May 20, 685) was the King of Northumbria from 670 until his death. He ruled over Northumbria when it was at the height of its power, but his reign ended with a disastrous defeat in which he lost his life.Ecgfrith was the son of his predecessor as king, Oswiu of Northumbria. Bede tells us, in his Historia ecclesiastica gentis Anglorum, that Ecgfrith was held as a hostage "at the court of Queen Cynwise in the province of the Mercians" at the time of Penda of Mercia's invasion of Northumbria in 654 or 655. Penda was, however, defeated and killed by the Northumbrians under Oswiu in the Battle of Winwaed, a victory which greatly enhanced Northumbrian power.
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