(mə-drĭdʹ). The capital and largest city of Spain, on the central plateau north-northeast of Toledo. Built on the site of a Moorish fortress captured in the 10th century, it became the capital in 1561 during the reign of Philip II and grew in importance and magnificence under the Bourbons in the 18th century. Madrid was a Loyalist stronghold during the Spanish Civil War (1936-1939). Population, 3,200,234, Madrid.