Guernsey, a History for tourism. Culture, People and Environment. Find out about this country's background information: A British Crown dependency, which, along with the other Channel Islands, remained loyal to the English monarchy when King John lost Normandy to France in 1204, Guernsey has some 1500 years of recorded history having been settled by Britons migrating to Brittany in the 5th century. Part of the medieval Duchy of Normandy, it became...