Jersey (/ˈdʒɜːrzi/ JUR-zee; Jèrriais: Jèrri [ʒɛri]), officially the Bailiwick of Jersey, is an autonomous and self-governing British Crown Dependency in Northwestern Europe 14 miles (23 km) off the Cotentin Peninsula of north-west France. At 45 square miles (120 km), the main island, Jersey, is the largest of the Channel Islands. Although not a sovereign state, Jersey has its own legal, fiscal and governmental systems; on that basis, it is regarded as a small nation or island country. Jersey's territory also includes some surrounding uninhabited islands and rocks. As of 2021, the island had a population of 103,267.
Historically part of the Duchy of Normandy, Jersey remained loyal to the English Crown when the English kings lost mainland Normandy, but it never became part of the Kingdom of England. From then until the end of the Napoleonic Wars, Jersey was at the frontline of Anglo-French Wars and was invaded a number of times, leading to the construction of fortifications such as Mont Orgueil Castle and to a thriving smuggling industry. The island was invaded and occupied by Nazi German forces during the Second World War until 9 May 1945, now celebrated as the island's national day.