History of the Britons (Historia Brittonum)

According to Wikipedia: "Nennius was a Welsh monk of the 9th century. He has traditionally been attributed with the authorship of the Historia Brittonum, based on the prologue affixed to that work, This attribution is widely considered a secondary (10th century) tradition. Nennius was a student of Elvodugus, commonly identified with the bishop Elfodd who convinced British ecclesiastics to accept the Continental dating for Easter, and who died in 809 according to the Annales Cambriae. Nenniu...