Brittany (French: Bretagne) is a cultural and administrative region in the north-west of France. Previously as a kingdom and then as a duchy, Brittany was a fief of the Kingdom of France. Brittany has also been referred to as Less, Lesser or Little Britain (as opposed to Great Britain). It is one of the six Celtic nations.
Brittany occupies a large peninsula in the north west of France, lying between the English Channel to the north and the Bay of Biscay to the south. Its land area is 34,023 km² (13,136 sq mi). The historical province of Brittany is divided into five departments: Finistère in the west, Côtes-d'Armor in the north, Ille-et-Vilaine in the north east, the Loire-Atlantique in the south east and Morbihan in the south on the Bay of Biscay.

During World War II, the government of Vichy France detached the Loire-Atlantique département (around the city of Nantes) from Brittany, and placed it within a region based on the city of Angers. Today, 80% of historic Brittany has become the administrative Region of Brittany, while the remaining area of the old Brittany, the Loire-Atlantique département around Nantes (formerly one of the historic capitals of Brittany), forms part of the Pays de la Loire region.
In January 2007 the population of historic Brittany was estimated to be 4,365,500. Of these, 71% lived in the région of Brittany, while 29% lived in the région of Pays-de-la-Loire. At the 1999 census, the largest metropolitan areas were Nantes (711,120 inhabitants), Rennes (521,188 inhabitants), and Brest (303,484 inhabitants).