Harrison appears to have taken `Erkenwijn' (recte Aescwine) as the first king of the East Saxons from the Historia Anglorum of Henry, archdeacon of Huntingdon. As a clergyman in the diocese of London he may also have been influenced by the early importance of Earconwald (d. 693), the bishop of the East Saxons who had his see in London, and whose tomb in St Paul's was the focus for a major cult until the Reformation.