Robert I (after September 866 – June 15, 923), king of West Francia (922 – 923), was the younger son of Robert the Strong, count of Anjou, and the brother of Odo of France. Robert I was at the Siege of Paris in 885. Robert had the title of "Dux Francorum". He did not call himself king of West Francia when his brother died in 898. Instead he served the Carolingian king, Charles the Simple and defended northern Francia from the attacks of the Norsemen.