Brittany (; French: Bretagne [bʁətaɲ] (listen); Breton: Breizh, pronounced [bʁɛjs] or [bʁɛx]; Gallo: Bertaèyn [bəʁtaɛɲ]) is a cultural region in the west of France, covering the western part of what was known as Armorica during the period of Roman occupation. It became an independent kingdom and then a duchy before being united with the Kingdom of France in 1532 as a province governed as a separate nation under the crown.
Brittany has also been referred to as Less, Lesser or Little Britain (as opposed to Great Britain, with which it shares an etymology). It is bordered by the English Channel to the north, Normandy to the northeast, eastern Pays de la Loire to the southeast, the Bay of Biscay to the south, and the Celtic Sea and the Atlantic Ocean to the west. Its land area is 34,023 km2 (13,136 sq mi).
Brittany is the site of some of the world's oldest standing architecture, home to the Barnenez, the Tumulus Saint-Michel and others, which date to the early 5th millennium BC. Today, the historical province of Brittany is split among five French departments: Finistère in the west, Côtes-d'Armor in the north, Ille-et-Vilaine in the northeast, Morbihan in the south and Loire-Atlantique in the southeast. Since a 1940s reorganisation under Vichy France, the modern administrative region of Brittany has controversially excluded the Loire-Atlantique department around Nantes, which now forms part of the Pays de la Loire region.
At the 2010 census, the population of historic Brittany was estimated to be 4,475,295. Of these, 71% lived in the region of Brittany, while 29% lived in the Loire-Atlantique department. In 2017, the largest metropolitan areas were Nantes, (972,828 inhabitants), Rennes (733,320 inhabitants), and Brest (321,364 inhabitants). Brittany is the traditional homeland of the Breton people and is one of the six Celtic nations, retaining a distinct cultural identity that reflects its history. A nationalist movement seeks greater autonomy within the French Republic.