 Evidence suggests that during the period between the death of Edmund the Martyr and the return of Guthrum to East Anglia in 880, Oswald and Æthelred ruled the East Angles as client kings.It is possible that the East Anglian aristocracy had been almost, but not entirely, extinguished by the Viking attacks that resulted in Edmund's death, and that in the years when Oswald, Æthelred and Guthrum successively ruled the kingdom, there was a period of opposition or defiance against the Danish leadership.The Vikings ruled the East Angles from the accession of Oswald, until 920, when East Anglia was incorporated into the kingdom of England after the defeat of the Danes by Edward the Elder.