Arthur I, Duke of Brittany
Arthur I was 4th Earl of Richmond and Duke of Brittany between 1196 and 1203. He was the posthumous son of Geoffrey II, Duke of Brittany, and Constance, Duchess of Brittany. His father, Geoffrey, was the son of Henry II, King of England. Wikipedia
Born: March 29, 1187, Nantes, France
Died: April 3, 1203 (age 16 years), Normandy, France
Place of burial: Cathédrale Notre-Dame de Rouen, Rouen, France
Siblings: Eleanor, Fair Maid of Brittany