The Region of León, Leonese region or Leonese Country (Leonese: País Llionés, región de León and rexón de Llión) is a historic territory defined by the 1833 Spanish administrative organisation. The Leonese region encompassed the provinces of Salamanca, Zamora, and León, now part of the modern Spanish autonomous community of Castile and León. As is the case with other historical regions, and continuing with centuries of history, the inhabitants of the Leonese region are still called Leonese. Even today, according with official autonomous government, the historical territorial adjective is used in addition with the modern annexed territory, the rest of Old Castile, being "Castilians and Leonese".
In 1983 the provincial government of León supported autonomy for the province of León, as did municipalities such as León and Ponferrada, the biggest cities in León, but this proposal was rejected by the Tribunal Constitucional (Constitutional Court of Spain).
The idea of constituting the Leonese Region as an autonomous community within Spain has been promoted by a number of Spanish regional political parties such as Partido Regionalista del País Leonés, Grupo Autonómico Leonés, Unión del Pueblo Leonés and Unión del Pueblo Salmantino. This movement receives the name of Leonesism.
Until 1833, the formerly independent Kingdom of León, situated in the northwest region of the Iberian Peninsula, retained the status of a kingdom although dynastic union had brought it into the Crown of Castile. The Kingdom of León was founded in 910 A.D. when the Christian princes of Asturias along the northern coast of the peninsula shifted their main seat from Oviedo to the city of León. The Atlantic provinces became the Kingdom of Portugal in 1139, and the eastern, inland part of the kingdom was joined dynastically to the Kingdom of Castile first in 1037–1065, again 1077–1109 and 1126–1157, 1230–1296 and from 1301 onward (see Castile and León § Historic union of the Kingdoms of Castile and León).