A central district of Spain, divided by the mountains of Castile into Old Castile (1,800) in the N., and New Castile (3,500) in the S.: the former consisting of a high bare plateau, bounded by mountains on the N. and on the S., with a variable climate, yields wheat and good pasturage, and is rich in minerals; the latter, also tableland, has a richer soil, and yields richer produce, breeds horses and cattle, and contains besides the quicksilver mines of Almaden. Both were at one time occupied by the Moors, and were created into a kingdom in the 11th century, and united to the crown of Spain in 1469 by the marriage of Ferdinand and Isabella.