 In 774 , Æthelbert called a council which deposed Alhred the King of Northumbria and sent the ex @-@ king north into exile with the Picts . The cause of the deposition may have been related to missionary work . The historian D. P. Kirby feels that Æthelbert was not a supporter of Alhred prior to his deposition . Alhred was replaced with Æthelred , who was replaced in 778 by Ælfwald , the son of <unk> . Kirby sees Æthelbert 's withdrawal of support as instrumental in the deposition of Æthelred , noting that Ælfwald was closely related to Æthelbert , unlike both Alhred and Æthelred . Kirby also notes that medieval chroniclers noted that Æthelbert is said to have not " spared evil kings " . 
