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
Henry I of England with William against Robert. Henry was present when William died in a hunting accident in 1100, and he seized the English throne, promising at his coronation to correct many of William's less popular policies. Henry married Matilda of Scotland but continued to have a large number of mistresses by whom he had many illegitimate children. Robert, who invaded in 1101, disputed Henry's control of England; this military campaign ended in a negotiated settlement that confirmed Henry as king. The peace was short-lived, and Henry invaded the Duchy of Normandy in 1105 and 1106, finally defeating Robert at the Battle of