The Anglo-Saxon Chronicle

A. D. 655. This year Penda was slain at Wingfield, and thirty royal personages with him, some of whom were kings. One of them was Ethelhere, brother of Anna, king of the East-Angles. The Mercians after this became Christians. From the beginning of the world had now elapsed five thousand eight hundred and fifty winters, when Peada, the son of Penda, assumed the government of the Mercians. In his time came together himself and Oswy, brother of King Oswald, and said, that they would rear a minster to the glory of Christ, and the honour of St. Peter. And they did so, and gave it the name of Medhamsted; because there is a well there, called Meadswell. And they began the groundwall, and wrought thereon; after which they committed the work to a monk, whose name was Saxulf. He was very much the friend of God, and him also loved all people. He was nobly born in the world, and rich: he is now much richer with Christ. But King Peada reigned no while; for he was betrayed by his own queen, in Easter-tide. This year Ithamar, Bishop of Rochester, consecrated Deus-dedit to Canterbury, on the twenty-sixth day of March.