Normans
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.
According to the Rolls of the Norman Exchequer in 1180 Jersey was divided for administrative purposes into three Ministeria: de Gorroic, de Groceio and de Crapaudoit (possibly each containing four parishes each).
The islands remained part of the Duchy of Normandy until 1204 when King Philip II Augustus of France conquered the duchy from King John of England; the islands remained in the personal possession of the king and were described as being a Peculiar of the Crown. The so-called Constitutions of King John are the foundation of modern self-government.
Read more about this topic: History Of Jersey