Ferdinand II of Aragon

Ferdinand II (10 March 1452 – 23 January 1516), called the Catholic, was King of Aragon from 1479 until his death. In 1469, he married Infanta Isabella, the future queen of Castile, which was regarded as the marital and political "cornerstone in the foundation of the Spanish monarchy". As a consequence of the marriage, in 1474 he became de jure uxoris King of Castile as Ferdinand V, when Isabella held the crown of Castile, until her death in 1504. At Isabella's death the crown of Castile passed to their daughter Joanna, by the terms of their prenuptial agreement and Isabella‘s last will and testament, and Ferdinand lost his monarchical status in Castile. Joanna's husband Philip became de jure uxoris King of Castile, but died in 1506, and Joanna ruled in her own right. In 1504, after a war with France, he became King of Naples as Ferdinand III, reuniting Naples with Sicily permanently and for the first time since 1458. In 1506, as part of a treaty with a France, Ferdinand married Germaine of Foix of France, but Ferdinand's only son and child of that marriage died soon after birth. (Had the child survived, the personal union of the crowns of Aragon and Castile would have ceased.) In 1508, Ferdinand was recognized as regent of Castile, following Joanna's alleged mental illness, until his own death in 1516. In 1512, he became King of Navarre by conquest.