(English) A kingdom on the Iberian peninsula, today in the country of Spain. Technically, Spain's New World possessions belonged only to two kingdoms, Castile and León, because they were responsible for the expeditions of conquest.
A former kingdom, Castile (Spanish: Castilla; usually pronounced Cast-EEL in English), gradually merged with its neighbors to become the Kingdom of Spain. in modern-day Spain, it comprises the regions of Castilla y LeÃ³n in the north-west, and Castilla-La Mancha in the center of the country. Modern Spanish monarchs are numbered according to the system of Castile.