However, the repeated attacks of Cadell and Hywel were recorded in Asser's Life of King Alfred, where it states Hyfaidd was replaced by his brother Rhodri, although the cause of his death is unknown.
Asser's Life of King Alfred details the repeated assaults on Hyfaidd by Cadell and Hywel, leading to his replacement by his brother Rhodri. The exact cause of Hyfaidd's death is not specified in the text.