History of Bristol Welsh estate and Robert of Caen became the first Earl of Gloucester, c. 1122. He is believed to have been responsible for completing Bristol castle. In 1135 Henry I died and the Earl of Gloucester rallied to the support of his sister Matilda against Stephen of Blois who had seized the throne on Henry's death. Stephen attempted to lay siege to Robert at Bristol in 1138 but gave up the attempt as the castle appeared impregnable. When Stephen was captured in 1141 he was imprisoned in the castle, but when Robert was captured by Stephen's forces, Matilda was forced to
Battle of the Standard and in the settling of regained territory, he had drawn on the talent and resources of the Anglo-Norman lands. The death of Henry I in 1135, weakening England, made David more reliant on his native subjects, and allowed him to contemplate winning control over substantial areas of northern England. Henry I had wished his inheritance to pass to his daughter Matilda, and in 1127 made his notables swear an oath to uphold the succession of Matilda (David was the first layman to do so). Many of the English and Norman magnates and barons were against Matilda because she was married