In the late 15th century Castile and Aragón were united under the famous Catholic monarchs, Ferdinand and Isabel, to create the modern unitary country of Spain. Navarre, enclosed between the two newer but increasingly stronger kingdoms, soon lost its early advantage and receded to secondary status.

Castile: History. Enter your search terms: The name Castile derives from the many castles built there by the Christian nobles early in the reconquest from the Moors (8th–9th cent.). Old Castile at first was a county of the kingdom of León, with Burgos its capital.

The region formed the core of the Kingdom of Castile, under which Spain was united in the late 15th and early 16th centuries. The name Castile—meaning “land of castles”—is first known to have been used in about ad 800, when it was applied to a small district at the foot of the Cantabrian Mountains in the extreme north of the modern province of Burgos.

The impact and early significance of castles in Spain can be measured by the fact that the noun “castle” (from the Latin castella meaning “castles”) forms the origin of the name of Spain’s historically most powerful kingdom: Castile. And the history of Castile –the land of castles– projects itself widely over the history of Spain, and its language —el castellano— has become a …

Henry III of Castile (1379 - 1406), called the Mourner (Spanish: Enrique el Doliente), was the son of John I and Eleanor of Aragon. He succeeded his father as King of Castile in 1390. Shortly after his birth, he was promised to be married to Beatrice of Portugal, the heir to the Portuguese throne.