REFN: 4446AN Alias:<ALIA> /Aethelred/ REFN: P4447 Æthelred I (866-71 AD) Anglo-Saxon king of Wessex, and son of King Æthelwulf, who ruled England during a time of gre at pressure from the invading Danes. He was an affable man, a devoutly religi ous man and the older brother of Alfred the Great, his second-in-command in t he resistance against the invaders. Together, they defeated the Danish kings Bagseg and Halfdan at the battle of Ashdown in 870.