The Christianisation of Anglo-Saxon England was a process spanning the 7th century. It is essentially the result of the Gregorian mission of 597, which was joined by the efforts of the Hiberno-Scottish mission from the 630s. From the 8th century, the Anglo-Saxon mission was in turn instrumental in the conversion of the population of the Frankish Empire.
Æthelberht of Kent was the first king to accept baptism, circa 601. He was followed by Rædwald of East Anglia and Saebert of Essex in 604. However, when Æthelberht and Saebert of Essex died in 616 they were both succeeded by pagan sons who were hostile to Christianity and drove the missionaries out, encouraging their subjects to return to their native paganism. Christianity only hung on with Rædwald, who was still worshiping the pagan gods alongside Christ.
The first Archbishops of Canterbury during the first half of the 7th century were members of the original Gregorian mission. The first native Saxon to be consecrated archbishop was Deusdedit of Canterbury, enthroned in 655. The first native Anglo-Saxon bishop was Ithamar, enthroned as Bishop of Rochester in 644.
The decisive shift to Christianity occurred in 655 when King Penda was slain in the Battle of the Winwaed and Mercia became officially Christian for the first time. The death of Penda also allowed Cenwalh of Wessex to return from exile and return Wessex, another powerful kingdom, to Christianity. After 655, only Sussex and the Isle of Wight remained openly pagan, although Wessex and Essex would later crown pagan kings. In 686 Arwald, the last openly pagan king was slain in battle and from this point on all Anglo-Saxon kings were at least nominally Christian (although there is some confusion about the religion of Caedwalla who ruled Wessex until 688).