Arthur I

Arthur I 1187-1203?, duke of Brittany (1196-1203?), son of Geoffrey, fourth son of Henry II of England and Constance, heiress of Brittany. Arthur, a posthumous child, was proclaimed duke in 1196, and an invasion by his uncle King Richard I of England was repulsed with French aid. Subsequently, Arthur was brought up at the court of King Philip II of France. On Richard's death (1199), Arthur's claim to the English crown was passed over in favor of his uncle John , youngest son of Henry II. Arthur allied himself with Philip II, who invested him with all of Richard's fiefs in France. The nobles of Anjou, Maine, and Touraine recognized Arthur as their ruler, but the young duke was captured (1202) by John while attempting to subdue Poitou. He was imprisoned in Rouen; his fate is uncertain, although John was suspected of murdering him in 1203. His story is told in Shakespeare's King John. Arthur's sister and heir married Pierre Mauclerc, who later became duke of Brittany as Peter I .

Arthur, Prince (1187–c.1203). As the posthumous only son of Geoffrey and Constance of Brittany, Arthur was duke of Brittany from the moment of his birth. Greater prospects opened up in 1190 when his uncle, Richard I, nominated him as heir presumptive to the throne, but by 1199, when Richard died, John had taken over as the acknowledged successor. Arthur's moment came in 1202 when King Philip Augustus, at war against John, decided to recognize him as rightful ruler of Normandy and Anjou. Unfortunately for Arthur he was captured by John in August 1202, imprisoned at Rouen, and never seen again. Ever since the image of the murdered prince has done much damage to John's reputation.