Robert Fitzroy, 1st Earl of Gloucester (before 1100 – 31 October 1147) (alias Robert Rufus, Robert de Caen, Robert Consul) was an illegitimate son of King Henry I of England. He was the half-brother of the Empress Matilda, and her chief military supporter during the civil war known as The Anarchy, in which she vied with Stephen of Blois for the throne of England.