Normandy is a region of northern France occupying the lower Seine area (upper or Haute-Normandie) and the region to the west (lower or Basse-Normandie) as far as the Cotentin Peninsula. Upper Normandy consists of the French départements of Seine-Maritime and Eure, and lower Normandy of the départements of Orne, Calvados, and Manche. Normandy was historically a province of France.
Normandy contains 3.2 million inhabitants, with an average population density of 107 per square kilometre, just under the national average, but rising to 145 for upper Normandy. The principal cities are Rouen (population 385,000, including suburbs), the capital of upper Normandy and formerly of the whole province; Le Havre (247,000); Caen (200,000), the capital of lower Normandy; and Cherbourg (89,000).
Normandy was the home of the Norman people in the early Middle Ages, the last people to successfully invade England. The Normans comprised a mixture of the earlier French and of the Vikings under the leadership of Rollo (Gånge Rolf), who besieged Paris and received the area of Normandy (Treaty of St.-Claire-sur-Epte, 911) in return for defending it against future pirate attacks.
Rollo's descendant William, Duke of Normany, invaded England in 1066 and became king William I of England. Normandy remained associated with England until 1087, in 1106-1144 and in 1154-1204, and was occupied by English forces during the Hundred Years' War in 1346-1360 and again in 1415-1450.
Normandy was also the site during World War II of the Normandy Invasion of German-occupied France by U.S., British, and Canadian troops. This campaign, also known as Operation Overlord, started on D-Day, June 6, 1944. Caen suffered severely in the fighting for the province, which continued until the liberation of Le Havre (September 12).
Since the Channel Islands are still under governance of the British, yet not part of the UK but rather the Duchy of Normandy, the British monarch (currently Queen Elizabeth II) is toasted Duke of Normandy. However, she is not technically Duke of Normandy as any claims by a British monarch to the title were given up by the Treaty of Paris (1295) and furthermore, the rights of succession of that title were governed under Salic Law.