Ferdinand II of Aragon

Ferdinand II (also known as Ferdinand I; Ferdinand III; and Ferdinand V; called Ferdinand the Catholic; 10 March 1452 – 23 January 1516) was King of Aragon from 1479 until his death in 1516. As the husband and co-ruler of Queen Isabella I of Castile, he was also King of Castile from 1475 to 1504 (as Ferdinand V). He reigned jointly with Isabella over a dynastically unified Spain; together, they are known as the Catholic Monarchs. Ferdinand is considered the de facto first king of Spain, and was described as such during his reign, even though, legally, Castile and Aragon remained two separate kingdoms until they were formally united by the Nueva Planta decrees issued between 1707 and 1716.

The Crown of Aragon that Ferdinand inherited in 1479 included the kingdoms of Aragon, Valencia, Mallorca, Sardinia, and Sicily, as well as the Principality of Catalonia. His marriage to Isabella is regarded as the "cornerstone in the foundation of the Spanish monarchy". They played a major role in the European colonization of the Americas, sponsoring the first voyage of Christopher Columbus in 1492. That year, the couple defeated Granada, the last Muslim state in Western Europe, thus completing the centuries-long Reconquista.