Historicity of King Arthur in the mid-10th century and gives the date of Badon as 516, and it lists Arthur's death as occurring in 537 at the Battle of Camlann. The annals survive in a version dating from the 10th century, and all other sources that name Arthur were written at least 400 years after the events which they describe. Arthur was first styled as a king of the Britons in Geoffrey of Monmouth's chronicle "Historia Regum Britanniae" (c. 1136). Geoffrey also makes Ambrosius Aurelianus (whom he calls Aurelius Ambrosius) a king of Britain and an older brother of Uther Pendragon, father of Arthur,
Historicity of King Arthur date ascribed to the "Historia Brittonum" which is usually attributed to Nennius, a Welsh ecclesiastic. "Historia Brittonum" lists 12 battles fought by Arthur and gives him the title of "dux bellorum" (war commander or leader), saying that Arthur fought "alongside the kings of the Britons", rather than that Arthur was himself a king. The list is inserted between the death of Hengist and the reign of Ida of Bernicia. Other accounts associating Arthur with the Battle of Badon can be shown to be derived directly or indirectly from the "Historia Brittonum". The earliest version of the "Annales Cambriae" was composed