History of Guernsey St Saviour, St Pierre du Bois, Ste. Marie du Catel, and the Vale. The loss of Normandy by King John in 1204 isolated the Channel Islands from mainland Europe. Each time England and France went to war over the coming centuries, trade to and from the Channel Islands was restricted or banned and even when not officially at war, the island was repeatedly attacked by continental pirates and naval forces. Fortifications were improved in the Channel Islands, manned by professional soldiers and the Guernsey militia who would help to defend the Island for the next 600 years. Service was compulsory
Maritime history of the Channel Islands at La Hougue Bie, Jersey give evidence of either populations living on or visiting the islands. Guernsey and Alderney were separated from mainland Europe around 7,000 BC with Jersey some time after, but even at 4,000 BC the islands were close to the mainland coast for basic boats to move between islands. Archaeological evidence of trade from the Iron Age period is in evidence in the Islands, with goods manufactured on the western coast such as armlets, Breton pottery and amphorae from the Mediterranean indicating trade along the Atlantic coast from Iberia to Ireland. Armorica was the nearest trade zone.