Why are Ferdinand II of Aragon and Isabella I of Castile known as the Catholic Monarchs?

Ferdinand II of Aragon was born on March 10, 1452 in Sos del Rey Católico, then only Sos, a town chosen intentionally by his mother. Isabella I of Castile, on the other hand, came into the world a year earlier: on April 22, 1451 in Madrigal de las Altas Torres. Together they formed one of the most important marriages in the history of the country, uniting with their marriage the dynasties of Aragon and Castile, laying the foundations of the Hispanic monarchy. They had five children: Isabel, Juan, Juana, María and Catalina.

Isabella I of Castile was the first to die: on November 26, 1504, in Medina del Campo. Twelve years later, Ferdinand would do it: January 23, 1516, in Madrigalejo. Before that, they had been recognized with the title that has passed to posterity: the Catholic Monarchs. Like all the appellatives with which history remembers the monarchs, this one also has an explanation.

Universal, yes, but above all Catholic

Catholic Monarchs

Sepulchre of the Catholic Monarchs, in Granada. | Javi Guerra Hernando, Wikimedia

Although on many occasions reference has been made to the Greek origin of the word catholic to explain this title, its concession has nothing to do with this. It is curious to note, in any case, that Greek classics such as Aristotle used the word καθολικός (katholikós) to speak of something universal. The Catholic Monarchs, as is well known, have a lot of universal, for it was under their reign and patronage that the conquest of America took place.

But this appointment is entirely related to the Catholic Church and the moment that Christianity was living in the European continent. That Ferdinand and Isabella became known as the Catholic Monarchs is due to the Valencian Pope Alexander VI, who certified it in a bull issued in December 1496. At that time, it was very common for monarchs to receive this kind of distinctions related to the faith.

The truth is that few had such a close relationship with the faith. Ferdinand and Isabella consummated the religious unification of the Spanish geography, conquered Granada, expelled the Jews and helped the papacy in the defense of their territories against France. This was the ultimate reason for its concession, since the defeat of the French would not have been possible without the help of the, by then, future Catholic Monarchs. For Pope Alexander VI, it was the greatest proof of his involvement with Catholicism.

At first, the title that was considered was ‘Very Catholic Monarchs’, but it was finally shortened to Catholic Monarchs. They were awarded this distinction for their role in promoting ‘the prosperity of Christians’ and also for their ‘defense of the Church and the faith’. Both left this world thus considered and have always been remembered in this way.


About the author