Anjou is a former county (in the sense of being ruled by a count, from c. 880), duchy (1360) and province centred on the city of Angers in the lower Loire Valley of western France. Its traditional Latin name was Andegavia.
Anjou was united with the English Crown from 1151-1199, when Henry II, and, in turn, his (third) son Richard the Lionheart, inherited the county, and thus themselves became Counts of Anjou. At its peak, the Angevin Empire then spread from Ulster to the Pyrenees. But Richard had no legitimate issue, so in 1199 Anjou passed to his nephew, Arthur of Brittany (the posthumous son of Henry II’s fourth son, Geoffrey), while the Crown of England passed to Henry II’s fifth son and Richard’s youngest brother, John. Count Arthur was taken prisoner by John in 1203, and disappeared in murky circumstances. In 1204, the county as a whole was in turn seized by France. Its status was elevated to that of a duchy for Prince Louis, the second son of John II of France, and remained as such until the Revolution. Today, Anjou corresponds largely to the present-day département of Maine-et-Loire.