James I the Conqueror was King of Aragon, Count of Barcelona and Lord of Montpellier from 1213 to 1276; King of Majorca from 1231 to 1276; and Valencia from 1238 to 1276. His long reign of 62 years is not only the longest of any Iberian monarch, but one of the longest monarchical reigns in history, ahead of Hirohito but remaining behind Queen Victoria and Ferdinand III of Naples and Sicily. He saw the expansion of the Crown of Aragon in three directions: Languedoc to the north, the Balearic Islands to the southeast, and Valencia to the south. By a treaty with Louis IX of France, he achieved the renunciation of any possible claim of French suzerainty over the County of Barcelona and the other Catalan counties, while he renounced northward expansion and taking back the once Catalan territories in Occitania and vassal counties loyal to the County of Barcelona, lands that were lost by his father Peter II of Aragon in the Battle of Muret during the Albigensian Crusade and annexed by the Kingdom of France, and then decided to turn south. His great part in the Reconquista was similar in Mediterranean Spain to that of his contemporary Ferdinand III of Castile in Andalusia. One of the main reasons for this formal renunciation of most of the once Catalan territories in Languedoc and Occitania and any expansion into them is the fact that he was raised by the Knights Templar crusaders, who had defeated his father fighting for the Pope alongside the French, so it was effectively forbidden for him to try to maintain the traditional influence of the Count of Barcelona that previously existed in Occitania and Languedoc.

Catalan, known in the Valencian Community and Carche as Valencian, is a Western Romance language. It is the official language of Andorra, and an official language of three autonomous communities in eastern Spain: Catalonia, the Balearic Islands and the Valencian Community, where it is called Valencian. It has semi-official status in the Italian comune of Alghero, and it is spoken in the Pyrénées-Orientales department of France and in two further areas in eastern Spain: the eastern strip of Aragon and the Carche area in the Region of Murcia. The Catalan-speaking territories are often called the Països Catalans or "Catalan Countries".