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
William the Conqueror of the year on which fighting was permitted. Although the Battle of Val-ès-Dunes marked a turning point in William's control of the duchy, it was not the end of his struggle to gain the upper hand over the nobility. The period from 1047 to 1054 saw almost continuous warfare, with lesser crises continuing until 1060. William's next efforts were against Guy of Burgundy, who retreated to his castle at Brionne, which William besieged. After a long effort, the duke succeeded in exiling Guy in 1050. To address the growing power of the Count of Anjou, Geoffrey Martel, William joined with