Nennius (c. 9th Centruy) was a monk who has been traditionally attributed with the authorship of the Historia Brittonum. Nennius was a student of Elvodugus, commonly identified with the bishop Elfodd of Bangor who convinced British ecclesiastics to accept the Continental dating for Easter, and who died in 809 according to the Annales Cambriae. Nennius is believed to have lived in the area made up by Brecknockshire and Radnorshire in present-day Powys. Thus, he lived outside the Anglo-Saxon kingdoms, isolated by mountains in a rural society. Because of the lack of evidence concerning the life of Nennius he has become the subject of legend himself.