Isabella I; Isabella the Catholic
Queen of Castile, born Madrigtti de las Altas Torres, 1451; died Castle of La Mota, Medina del Campo (Valladolid), Spain, 1504.
In 1468 she defeated an attempt to make her usurp the crown of her brother, Henry IV, who made her his heir to the exclusion of his reputed daughter Joan, known as "La Beltraneja" on the supposition that Don Beltran was her real father; this pact, however, was later revoked.
Refusing all other alliances planned for her, in 1469 she married Prince Ferdinand of Aragon, against her brother's wishes.
On the death of Henry she was proclaimed Queen of Castile; her claim was contested by La Beltraneja, supported by Portugal, and a five years war ensued.
Ferdinand had meanwhile succeeded to the throne of Aragon, and thus the definitive unity of the Spanish nation was accomplished in the two monarchs, to whom Alexander VI gave the title of "Catholic" which the Kings of Spain still bear.
Among the great achievements of their joint reign were the conquest of Granada, 1492, which assured the territorial unity of the Spanish monarchy, and the discovery of America by Columbus, an enterprise in which the queen assisted materially.
She led the way in fostering the love of study and in many respects her court recalls that of Charlemagne.
New Catholic Dictionary