Roussillon was, along with
Cerdanya and
Conflent, the subject of a major
cartulary under Alfonso II or perhaps
Peter II: the
Liber feudorum Ceritaniae. It is a record of charters, usually related to castle- and land-holding in the three counties, from the archive of the counts of Barcelona. Surely as a reaction to the threat posed by the
anti-Cathar crusade in Languedoc led by French nobles, King
Peter II of Aragon granted around 1209 to his uncle
Sancho the county of Roussillon, including Conflent and those territories of upper Roussillon and Vallespir that had been part of the
County of Besalú. Therefore, the county of Roussillon again coincided with the
Diocese of Elna. Sancho I of Roussillon-Cerdanya, was succeeded by his son
Nuño Sánchez, on whose death in 1242, his Counties reverted to the Crown of Aragon. In his will of 1261, King
James I of Aragon stipulated that the Counties of Roussillon and
Cerdanya were to become part of the
Kingdom of Mallorca, which would correspond to his second son
James, being separated from Aragon, Catalonia and Valencia which would be for his eldest son
Peter. From then on, the infante James administered his future kingdom as a
Governor. On the death of James I in 1276, this testament was put into practice, and the counties of Roussillon and Cerdanya came under the control of King
James II of Mallorca (1276–1311), who made Perpignan the second capital of the Kingdom. The County of Roussillon, and the rest of the Kingdom of Mallorca, was reunited with the Kingdom of Aragon after
a military campaign in 1343-1344 by King
Peter IV of Aragon. Between 1462 and 1492, the County of Roussillon was occupied by France. At the outbreak of the
Catalan Civil War, in the Treaty of Bayonne, King
John II of Aragon ceded to King
Louis XI of France the jurisdiction, rights and income of the counties of Roussillon and Cerdagne, as long as the King of Aragon did not make effective the payment of 200,000 escudos, in exchange for Louis XI providing him with military aid to subdue the rest of Catalonia. When the War ended in 1472, France had switched sides and had supported the Council of the Principality of Catalonia. John II of Aragon invaded Roussillon and Cerdagne to expel the French, but didn't succeed after 3 years of fighting. Finally, Roussillon and Cerdagne were returned to Aragon in the
Treaty of Barcelona (1493), as a price for
Ferdinand II of Aragon's promise to maintain neutrality during
Charles VIII of France's forthcoming invasion of the
Kingdom of Naples. 166 years later, in the
Treaty of the Pyrenees (1659), the County of Roussillon was definitively ceded to the Kingdom of France. ==List of counts==