Kingdom of Castile

The Kingdom of Castile was a polity in the Iberian Peninsula during the Middle Ages. It traces its origins to the 9th-century County of Castile, as an eastern frontier lordship of the Kingdom of León. During the 10th century, the Castilian counts increased their autonomy, but it was not until 1065 that it was separated from the Kingdom of León and became a kingdom in its own right. Between 1072 and 1157, it was again united with León, and after 1230, the union became permanent.

Throughout that period, the Castilian kings made extensive conquests in southern Iberia at the expense of the Islamic principalities. The Kingdoms of Castile and of León, with their southern acquisitions, came to be known collectively as the Crown of Castile, a term that also came to encompass overseas expansion.

History

9th to 11th centuries: beginnings

According to the chronicles of Alfonso III of Asturias, the first reference to the name "Castile" (Castilla) can be found in a document written during AD 800. In the Al-Andalus chronicles from the Cordoban Caliphate, the oldest sources refer to it as Al-Qila, or "the castled" high plains past the territory of Alava, further south than it and the first encountered in their expeditions from Zaragoza. The name reflects its origin as a march on the eastern frontier of the Kingdom of Asturias, protected by castles, towers, or castra, in a territory formerly called Bardulia.

The County of Castile, bordered in the south by the northern reaches of the Spanish Sistema Central mountain system, was just north of modern-day Madrid province.