GLOUCESTER, ROBERT, EARL OF (d. 1147), was a natural son of Henry I. of England. He was born, before his father's accession, at Caen in Normandy; but the exact date of his birth, and his mother's name are unknown. His father married him to a daughter of Robert Fitz Hamon, heiress of the lordships of Gloucester and Glamorgan. About 1121 the earldom of Gloucester was created for his benefit. After his father's death, he was sedulously courted by the rival parties of his half-sister the empress Matilda and of Stephen. He tendered his homage to Stephen upon strict conditions, the breach of which should be held to invalidate the contract. But in 1137 Robert left England for Normandy, renewed his relations with the Angevin party, and in 1138 sent a formal defiance to the king. Returning to England in 1139, he revolted, and won the greater part of western England and the south Welsh marches for the empress. By the battle of Lincoln (Feb. 2, 1141), in which Stephen was taken prisoner, the earl made good Matilda's claim to the whole king dom. He accompanied her to Winchester and London ; but was captured by the king's supporters after the siege of Winchester. He was exchanged for Stephen, and after his release continued to fight for Matilda until his death on Oct. 31, 1147. Robert hardly deserves the extravagant praise which is lavished upon him by William of Malmesbury. The sympathies of the chronicler are too obviously influenced by the earl's munificence towards literary men.
See the Historia novella by William of Malmesbury (Rolls edition) ; the Historia Anglorum by Henry of Huntingdon (Rolls edition) ; J. H. Round, Geoffrey de Mandeville (1892) ; and O. Rossler, Kaiserin Mathilde (1897) .