The Kingdom of León (Leonese: Reinu de Llïón, Spanish: Reino de León, Galician: Reino de León, Portuguese: Reino de Leão, Latin: Regnum Legionense) was an independent kingdom situated in the northwest region of the Iberian Peninsula. It was founded in AD 910 when the Christian princes of Asturias along the northern coast of the peninsula shifted their capital from Oviedo to the city of León. The County of Portugal separated to become the independent Kingdom of Portugal in 1139 and the eastern, inland part of León was joined to the Kingdom of Castile in 1230.
From 1296 to 1301, the Kingdom of León was again independent and after the re-union with Castile remained a Crown until 1833, but as part of a united Spain from 1479. In the Royal Decree of 30 November 1833, the Kingdom of León was considered one of the Spanish regions and divided into the provinces of León, Zamora and Salamanca. In 1978, these three provinces of the region of León were included along with six provinces of the historic region of Old Castile to create the autonomous community of Castile and León. However, significant parts of the former kingdom today integrate these three provinces and the autonomous communities of Extremadura, Galicia and Asturias.