The Kingdom of Castile (/ k æ ˈ s t iː l /; Spanish: Reino de Castilla, Latin: Regnum Castellae) was a large and powerful state on the Iberian Peninsula during the Middle Ages.Its name comes from the host of castles constructed in the region. It began in the 9th century as the County of Castile (Condado de Castilla), an eastern frontier lordship of the Kingdom of León.

A type of monarchy; A realm ruled by: . A king, during the reign of a male monarch; A queen regnant, during the reign of a female monarch; Taxonomy. Kingdom (biology), a category in biological taxonomy Arts and media Television. Kingdom (British TV series), a 2007 British television drama starring Stephen Fry; Kingdom (American TV series), a 2014 US television …