Arthur I, Duke of Brittany

Arthur I was the posthumous son of Geoffrey II, Duke of Brittany, and Constance, Duchess of Brittany, born on 29 March 1187. He became the Duke of Brittany from 1196 until his presumed death in 1203 and was also the 4th Earl of Richmond. Arthur’s father was the son of Henry II, King of England, placing Arthur within the line of succession to the English throne. In 1190, he was named heir to the throne of England and its French territories by his uncle, Richard I. However, following his capture in 1203 and subsequent incarceration at Rouen Castle, Arthur’s fate became unknown, with the general belief that he was killed by his other uncle, John.

Arthur’s early life was marked by political intrigue and the quest for independence for Brittany by his mother Constance. Despite plans for his betrothal and marriage to forge alliances, none came to fruition. After Richard I’s death, Arthur, then twelve, was seen as too young and under the influence of the French king, leading to John’s ascension to the English throne. Arthur’s claim to the throne led to his capture by John in 1202 and his eventual disappearance in 1203, which has since given rise to various theories and stories about his death.