Robert I, Duke of Normandy Robert I, Duke of Normandy Robert the Magnificent (; 22 June 1000 – 1–3 July 1035), was the Duke of Normandy from 1027 until his death in 1035. Owing to uncertainty over the numbering of the Dukes of Normandy he is usually called Robert I, but sometimes Robert II with his ancestor Rollo as Robert I. He was the son of Richard II and brother of Richard III, who preceded him as the Duke. Less than a year after his father's death, Robert revolted against his brother's rule, but failed. He would later inherit Normandy after his brother's death. He
John IV, Duke of Brittany John IV, Duke of Brittany John IV the Conqueror KG (in Breton Yann IV, in French Jean IV, and traditionally in English sources both John of Montfort and John V) (1339 – 1 November 1399) was Duke of Brittany and Count of Montfort from 1345 until his death and 7th Earl of Richmond from 1372 until his death. He was the son of John of Montfort and Joanna of Flanders. His father claimed the title Duke of Brittany, but was largely unable to enforce his claim for more than a brief period. Because his father's claim to the title was