Bede's Ecclesiastical History of England, ed. by A.M. Sellar, [1907], at sacred-texts.com
AT this time, the Middle Angles, that is, the Angles of the Midland country (probably Leicestershire)under their Prince Peada, the son of King Penda, received the faith and mysteries of the truth. Being an excellent youth, and most worthy of the name and office of a king, he was by his father elevated to the throne of that nation, and came to Oswy, king of the Northumbrians, requesting to have his daughter Aichfled given him to wife; but he could not obtain his desire unless he would receive the faith of Christ, and be baptized, with the nation which he governed. When he heard the preaching of the truth, the promise of the heavenly kingdom, and the hope of resurrection and future immortality, he declared that he would willingly become a Christian, even though he should not obtain the maiden; being chiefly prevailed on to receive the faith by King Oswy’s son Alchfrid,who was his brother-in-law and friend, for he had married his sister Cyneburg,3 the daughter of King Penda.
Accordingly he was baptized by Bishop Finan, with all his his nobles and thegns,and their servants, that came along with him, at a noted township, belonging to the king, called At the Wall. And having received four priests, who by reason of their learning and good life were deemed proper to instruct and baptize his nation, he returned home with much joy. These priests were Cedd and Adda, and Betti and Diuma; the last of whom was by nation a Scot, the others English. Adda was brother to Utta, whom we have mentioned before,a renowned priest, and abbot of the monastery which is called At the Goat’s Head.8The aforesaid priests, arriving in the province with the prince, preached the Word, and were heard willingly; and many, as well of the nobility as the common sort, renouncing the abominations of idolatry, were daily washed in the fountain of the faith.
Nor did King Penda forbid the preaching of the Word even among his people, the Mercians, if any were willing to hear it; but, on the contrary, he hated and despised those whom he perceived to be without the works of faith, when they had once received the faith of Christ, saying, that they were contemptible and wretched who scorned to obey their God, in whom they believed. These things were set on foot two years before the death of King Penda.
But when he was slain, and the most Christian king, Oswy, succeeded him in the throne, as we shall hereafter relate, Diuma,one of the aforesaid four priests, was made bishop of the Midland Angles, as also of the Mercians, being ordained by Bishop Finan; for the scarcity of priests made it necessary that one prelate should be set over two nations. Having in a short time gained many people to the Lord, he died among the Midland Angles, in the country called Infeppingum; and Ceollach, also of the Scottish nation, succeeded him in the bishopric. But he, not long after, left his bishopric, and returned to the island of Hii, which, among the Scots, was the chief and head of many monasteries. His successor in the bishopric was Trumhere,a godly man, and trained in the monastic life, an Englishman, but ordained bishop by the Scots. This happened in the days of King Wulfhere, of whom we shall speak hereafter.