The Reapers' War, also known as the Catalan Revolt, was a conflict that affected the Principality of Catalonia between the years of 1640 and 1659. It had an enduring effect in the Treaty of the Pyrenees (1659), which ceded the County of Roussillon and the northern half of the County of Cerdanya to France, splitting these northern Catalan territories off from the Principality of Catalonia and the Crown of Aragon, and thereby receding the borders of Spain to the Pyrenees.

The Crown of Aragon was a composite monarchy ruled by one king, originated by the dynastic union of the Kingdom of Aragon and the County of Barcelona and ended as a consequence of the War of the Spanish Succession. At the height of its power in the 14th and 15th centuries, the Crown of Aragon was a thalassocracy controlling a large portion of present-day eastern Spain, parts of what is now southern France, and a Mediterranean empire which included the Balearic Islands, Sicily, Corsica, Sardinia, Malta, Southern Italy and parts of Greece.