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 V, Count Palatine of the Rhine first he supported him, but switched sides to Philip of Swabia in 1203. Having divided the Welf allodial lands with his brothers Otto and William of Winchester, Henry then ruled over the northern Saxon territories around Stade and Altencelle and also was confirmed as count palatine by King Philip. When the German throne quarrel ended with Philip's assassination in 1208, Henry again sided with Otto IV. In Imperial service, he tried to ward off the territorial claims by the Rhenish Prince-archbishops of Cologne, Trier and Mainz, though to no avail. After the death of his cousin Arthur I, Duke of