Castile
Castile, a region and formerly a kingdom in northern and central Spain. In the northern part, called Old Castile, the leading cities are Santander and Burgos. Madrid and Toledo are in New Castile, to the south. Much of Spain's arid central plateau is in Castile. Sheep grazing is a major occupation. Castilian Spanish is the literary language of Spain.
In the 10th century, Old Castile was a small area off the Bay of Biscay. New Castile was founded in 1085 when Alfonso VI captured Toledo from the Moors. Castile became united with León, the kingdom to the west, in 1230. Aragon, the kingdom to the east, was permanently united with Castile in 1479 after the marriage of Isabella of Castile to Ferdinand of Aragon. The kingdom of Spain resulted from this union.