Arthur I (Breton: Arzhur; 29 March 1187 – presumably 1203) was 4th Earl of Richmond and Duke of Brittany between 1196 and 1203. He was the son of Duchess Constance of Brittany, born posthumously to Constance's first husband, Duke Geoffrey II. Through Geoffrey, Arthur was the grandson of King Henry II of England and Duchess Eleanor of Aquitaine,...
