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 December. The Empress Matilda did not give up her claim to England and Normandy, leading to the prolonged civil war known as the Anarchy between 1135 and 1153. Historians have drawn on a range of sources on Henry, including the accounts of chroniclers; other documentary evidence, including early pipe rolls; and surviving buildings and architecture. The three main chroniclers to describe the events of Henry's life were William of Malmesbury, Orderic Vitalis, and Henry of Huntingdon, but each incorporated extensive social and moral commentary into their accounts and borrowed a range of literary devices and stereotypical events from other popular