Chausey (ʃo.zɛ) is a group of small islands, islets and rocks off the coast of Normandy, in the English Channel. It lies from Granville and forms a quartier of the Granville commune in the Manche département. Chausey forms part of the Channel Islands from a geographical point of view, but, because it is under French jurisdiction, it is almost never mentioned in the context of the other Channel Islands. There are no scheduled transport links between Chausey and the other Channel Islands, although between two and four daily shuttles link Chausey to mainland France through Granville, depending on the season.
The -ey ending of the name Chausey may be assumed to be associated with the Norse -ey (meaning island), as seen not only in Jersey, Guernsey, Alderney, but also islands farther away like Anglesey, Orkney and Heimaey.
In 933, the Duchy of Normandy annexed the Channel Islands including Chausey, Minquiers and Ecrehous. In 1022, Richard II, Duke of Normandy, gave Chausey and the barony of Saint-Pair-sur-Mer to the Benedictine monks of Mont Saint-Michel, who built a priory on the Grande île.
The islands became subject to the Kingdom of England following the conquest of England by William, Duke of Normandy in 1066. However, in 1202, in a conflict with King John, Philip Augustus of France, claiming feudal overlordship of Normandy, summoned the English King to answer charges or forfeit all lands which he held in fee of the King of France. John refused to appear and, in 1204, Philip occupied continental Normandy, although he failed in his attempts to occupy the islands in the Channel. The 1259 Treaty of Paris confirmed the loss of Normandy but the retention of the "islands (if any) which the King of England should hold" under suzerainty of the King of France. The vassalage requirement was extinguished in the Treaty of Calais of 1360.
Chausey was for a long time an object of rivalry between England and France. Although the UK government has contended that, until about 1764, Chausey belonged to England, Chausey, unlike its Channel Islands neighbours, has, in fact, been French for centuries.