Born an illegitimate son of King Henry I of England about 1090 in Caen, he was consequently known as Robert de Caen. He witnessed charters of the King from about April 1113 onwards and fought at the battle of Bremule, on 20 August 1119, where King Henry I defeated Louis VI, King of France. Between June and September 1122 he was created Earl of Gloucester. In 1123 he brought a force to assist in the capture of the castle of Brionne held by the rebellious Norman barons. In 1126 he had custody of his uncle, Duke Robert of Normandy, as a prisoner at Bristol and later at Cardiff. In 1127 he did homage to the Empress Matilda, recognising her as his father's successor in the kingdom. On this occasion he had a dispute with his cousin, Stephen de Blois, as to precedence which was decided against him. In 1130 he sanctioned the foundation of the Abbey of Neath. In 1131, at the Council of Northampton, he took precedence among the five Earls who attended. In 1133 he was sent by the King to Bayeux, after the death of Bishop Richard, to enquire as to the fees and services due to the see by its barons, knights and vavasours. He was present at the King's death in December 1135 and received 60,000 livres from him, apparently as executor. On Stephen's accession to the English Crown and his recognition as Duke by the Normans, Robert gave up Falaise to his agents but removed his father's treasure. In March 1136 he returned to England and, after Easter, did homage for his English lands and, when Stephen granted his Charter of Liberties, he was a witness. At about this time or in the following year he founded St.James's Priory at Bristol as a cell to Tewkesbury, giving to the Lady Chapel of the Priory every tenth stone while building the keep of Bristol Castle at the same time. In 1137 he accompanied Stephen to Normandy. However, they quarrelled and next year his English and Welsh estates were forfeited. Thereupon he prepared for war with Stephen and took up the cause of his half-sister Matilda in Normandy, obtaining the surrender of Caen and Bayeux to her husband. In September 1139 he landed in England with Matilda and, taking her to Arundel Castle, became her commander in the civil war that ensued. In 1140 he burnt Nottingham and, in February 1141, he and his son-in-law, Ranulph, Earl of Chester, relieved Lincoln and took Stephen prisoner, sending him to Bristol. He accompanied Matilda in her progress to Winchester and London and, when the citizens drove her out, fled with her to Oxford. Taking part in the fighting at Winchester, he helped Matilda to escape from the city but, on 14 September 1141, was captured at Stockbridge and taken prisoner to Rochester. Shortly afterwards he was exchanged, without concessions on either side, for King Stephen. Robert then joined Matilda at Bristol and with her proceeded to Oxford. In June 1142 Matilda sent him over to her husband, Geoffrey of Anjou, to urge him to invade England. Geoffrey declined to help until he had conquered Normandy, whereupon Robert joined him in his campaign. When they received the news that Matilda was besieged in Oxford, Robert hurried back to help her, taking with him her son, the future King Henry II. He captured Wareham and other places and, on Matilda's escape from Oxford, he and Henry met her at Wallingford. In 1143 Robert defeated Stephen at Wilton and in 1144, blockaded Malmesbury, Stephen refusing battle. Matilda's party was now so much reduced that Stephen was able to take Faringdon, which had been fortified by Robert. In the spring of 1147 Robert took Henry (II) back to Wareham and sent him over to Anjou; in the same year he founded Margam Abbey. However, on 31 October 1147 he died of a fever at Bristol and was buried there in the Priory of St.James.
Source: Leo van de Pas