Isabella, name of 2 queens of Spain. Isabella I (1451–1504) was queen of Castille from 1474 and of Aragon 1479–1481. Her marriage to Ferdinand II unified Christian Spain; royal power was strengthened and the Inquisition reestablished, Isabella supporting its call for the expulsion of Spanish Jews. She financed Columbus's expedition in 1492, and helped direct the conquest of Moorish Granada. Isabella ll (1830–1904) was queen of Spain (1833–68). Her succession was disputed by the Carlists, provoking civil war (1833–39). Her personal rule proved arbitrary and ineffectual. She was deposed in 1868 and abdicated in 1870.