 According to Bede, Rædwald was recognised as exercising dominance or "imperium" over the southern Anglo-Saxon kingdoms, a position that was assured when he gave his loyalty and support to Edwin of Northumbria (who was at that time a fugitive at the East Anglian court) and together they defeated Æthelfrith of Northumbria on the banks of the River Idle, a tributary of the Trent.Rædwald was converted to Christianity in Kent at the invitation of King Æthelberht, but, under the influence of his pagan wife, his church contained both a Christian and a pagan altar.Upon his death in around 624, Rædwald was succeeded by his surviving son Eorpwald, who was then converted to the Christian faith shortly after becoming king.