 The island took the name Jersey as a result of Viking activity in the area between the 9th and 10th centuries.The Channel Islands remained politically linked to Brittany until 933, when William Longsword, Duke of Normandy seized the Cotentin and the islands and added them to his domain; in 1066, Duke William II of Normandy defeated Harold at Hastings to become king of England; however, he continued to rule his French possessions as a separate entity, as fealty was owed as a Duke, to the King of France.According to the Rolls of the Norman Exchequer, in 1180 Jersey was divided for administrative purposes into three ministeria