Written in 1136 by Geoffrey of Monmouth, the Historia Regum Britanniae (History of the Kings of Britain) purported to chronicle the British monarchy from the arrival of the Trojan Brutus, grandson of Aeneas, through to the seventh century AD. The Historia was a medieval best-seller, and copies spread across the whole of western Europe. It was the first work to outline the story of King Arthur. The Historia has long been dismissed as an unreliable...