Treaty of the Pyrenees
The Treaty of the Pyrenees (Spanish: Tratado de los Pirineos, French: Traité des Pyrénées, Catalan: Tractat dels Pirineus) was signed to end the 1635 to 1659 war between France and Spain, a war that was initially a part of the wider Thirty Years' War. It was signed on Pheasant Island, a river island on the border between the two countries. The kings Louis XIV of France and Philip IV of Spain were represented by their chief ministers, Cardinal Mazarin and Don Luis de Haro, respectively.
France entered the Thirty Years' War after the Spanish Habsburg victories in the Dutch Revolt in the 1620s and at the Battle of Nördlingen against Sweden in 1634. By 1640 France began to interfere in Spanish politics, aiding the revolt in Catalonia, while Spain in response aided the Fronde revolt in France in 1648. During the negotiations for the Peace of Westphalia in 1648, France gained Alsace and Lorraine and cut off Spanish access to the Netherlands from Austria, leading to open warfare between the French and Spanish.
After over ten years of war, an Anglo-French alliance was victorious at the Battle of the Dunes in 1658 and peace was settled by means of this treaty in 1659.
France gained Roussillon and Perpignan, Montmédy and other parts of Luxembourg, Artois and other towns in Flanders, including Arras, Béthune, Gravelines and Thionville, and a new border with Spain was fixed at the Pyrenees. However, the treaty stipulated only that all villages north of the Pyrenees should become part of France. For that reason there is an exclave of Spain in this part of France, the town of Llívia, considered a town and not a village, which remains under Spanish control and is part of the comarca of Baixa Cerdanya, the Spanish province of Girona. This border was not properly settled until the Treaty of Bayonne was signed in 1856.
Spain was forced to recognise and confirm all of the French gains at the Peace of Westphalia.
In exchange for the Spanish territorial losses, the French king pledged to quit his support for Portugal and renounced to his claim to the county of Barcelona, which the French crown was claiming ever since the Catalan Revolt (also known as Reapers' War). The Portuguese revolt in 1640, led by the Duke of Braganza was supported monetarily by Cardinal Richelieu of France. After the Catalonian Revolt France had controlled Catalonia from January 1641, when a combined Catalan and French force defeated the Spanish army at Montjuich, until 1652.
The treaty also arranged for a marriage between Louis XIV of France and Maria Theresa of Spain, the daughter of Philip IV of Spain. Maria Theresa was forced to renounce her claim to the Spanish throne, in return for a monetary settlement as part of her dowry. This settlement was never paid, a factor that eventually led to the War of Devolution in 1668.
The Treaty of the Pyrenees is the last major diplomatic achievement by Cardinal Mazarin. Combined with the Peace of Westphalia, it allowed Louis XIV remarkable stability and diplomatic advantage by means of a weakened Louis II de Bourbon, Prince de Condé and a weakened Spanish Crown, along the agreed dowry, which was an important element in the French king's strategy:
All in all, in 1660, when the Swedish occupation of Poland finished, most of European continent was at peace (Portuguese Restoration War, third stage), and the Bourbons had prevailed over the Habsburgs.
French annexations 
In the context of the territorial changes involved in the Treaty, France got some territorial gains, on both its northern and southern borders.
- In the north, France gained French Flanders.
- In the south, the northern part of Historical Catalonia, including Roussillon, Conflent, Vallespir, Capcir and French Cerdagne were transferred to France. The Albera Range, an eastern prolongation of the Pyrenees became the border between France and Spain. Every year on 7 November, Catalanists from this region, known nowadays in Catalonia as "Northern Catalonia", remember this event and demonstrate in Perpignan. In 2009 the demonstrations marked the 350 anniversary of the Treaty of the Pyrenees.
See also 
|Wikimedia Commons has media related to: Treaty of the Pyrenees|
- Maland M.A., David (1991). Europe in the Seventeenth Century (Second ed.). Macmillan. p. 227. ISBN 0-333-33574-0.
- Pendrill, Colin (2002). In Martin Collier, Erica Lewis. Spain 1474 - 1700. Heinemann Advanced History, The Triumphs and Tribulations of Empire. pp. 142–143. ISBN 978-0-435-32733-0.
- Perpinyà - 350 anys del Tractat dels Pirineus
- PDF (16.8 MiB), France National Archives Transcription (French)