In the Middle Ages, the duke of Normandy was the ruler of the Duchy of Normandy in north-western France. The duchy arose out of a grant of land to the Viking leader Rollo by the French king Charles the Simple in 911. In 924 and again in 933, Normandy was expanded by royal grant. Rollo's male-line descendants continued to rule it until 1135, and cognatic descendants ruled it until 1204. In 1202 the French king Philip II declared Normandy a forfeited fief and by 1204 his army had conquered it. It remained a French royal province thereafter, still called the Duchy of Normandy, but only occasionally granted to a duke of the royal house as an appanage.

The term Angevin Empire describes the possessions held by the House of Plantagenet during the 12th and 13th centuries, when they ruled over an area covering roughly all of present-day England, half of France, and parts of Ireland and Wales, and had further influence over much of the remaining British Isles. It may be described as an early example of a composite monarchy. The empire was established by Henry II of England, who succeeded his father Geoffrey as Duke of Normandy and Count of Anjou. Henry married Eleanor of Aquitaine in 1152, acquiring the Duchy of Aquitaine, and inherited his mother Empress Matilda's claim to the English throne, succeeding his rival Stephen in 1154. Although their title of highest rank came from the Kingdom of England, the Plantagenets held court primarily on the continent at Angers in Anjou, and at Chinon in Touraine.