If you’ve ever travelled to Spain, or read up on Spanish history, then you’ll have come across Isabella and Ferdinand. They are said to be the unifying monarchs of Spain, but what exactly did they do? How did they unify Spain? What made them so iconic? And why are the known as one of the greatest power couple of all time? Well, it’s a long story, but we’ll try to make it as brief as possible. So, here is a brief history of what makes Isabella of Castile and Ferdinand of Aragon so great.
Who Was Isabella of Castile
Before she became a queen, Isabella of Castile was the first born daughter of King John II of Castile, and as such, from an early age, she was already destined to expand her father’s kingdom. One of the ways in which she would help her father’s goal of unifying Spain was by being betrothed, at an early, to none other than her future husband, Ferdinand of Aragon. Of course, as she grew older, the agreement was forgotten and eventually broken, when she promised to marry a Portuguese king. But this sparked a civil war and it forced her to reconsider.

Later, after her father’s death in 1454, her half brother took the throne of Castile, and became King Henry IV of Castile. Initially, he brought her into his court, to keep an eye on her, but having shown she would not “play her role”, he eventually made an agreement with her, to name her his “heiress presumptive”. This means, that on his death, she would be the most likely candidate to take the throne. It also gave her the right to marry whomever she chose.
Who Was Ferdinand of Aragon
Ferdinand was a prince himself, but he was not initially in line to take his father’s throne. Not only that, but he also grew up in a conflicted kingdom, with many factions fighting to gain control of his father’s kingdom, one of which was created by his own brother. For his part, Ferdinand supported his father (who was also named John II), and this granted him significant military power, meaning he owed his leadership experience to the constant battles he’d had to fight, in order to secure his father’s throne and power.

Eventually, he too became the heir to his father’s throne, not least because he was his father’s favourite, but because his brother, Charles, Prince of Viana, died suddenly in 1461. From then on, the political burdens of the court became Ferdinand’s. And as such, he needed to gain the support of their neighbours, Castile. Of course, it was said that Ferdinand was a handsome man, who had great integrity and humility.
The Union Of Isabella And Ferdinand
It shouldn’t come as a shock that the marriage between Isabella and Ferdinand wasn’t a romantic one. It was initially simply for convenience. Ferdinand needed to expand the power of Aragon, to lift the region from Catalonian power, and Isabella needed a strong military presence, to secure her right to the throne of Castile. So, the pair married, against Henry’s wishes. Her half brother, it seems wanted her to marry the king of Portugal, King Afonso V, but ever the calculating princess, Isabella married Ferdinand, secretly. Thus, angering her half brother, which eventually led to him breaking the agreement he made to her.

This led to even more conflict, as Henry’s daughter, who many believed to actually be the daughter of a duke, called Beltrán, was then made heir apparent, and was backed by many anti-Aragonese groups at the time. After his death in 1474, all hell broke loose and Isabella and Ferdinand were at constant war with Joanna, who disputed Isabella’s claim to the throne. However, because Joanna’s military power proved ineffective, despite the support of her uncle, King Afonso of Portugal, who she married, the war, called the War of the Castilian Succession, ended with her stepping down and entering into a convent.
The Reign Of Isabella and Ferdinand
For many years, after the War of Castilian Succession, both Isabella and Ferdinand ruled Castile and Aragon, side by side. Meaning, they both had equal power, and they reigned as equals, which had been unheard of before. And in the aftermath, the pair were called the Catholic Monarchs, as both were firm believers in the Catholic faith. Not only that, but through their reign, they managed to unify Spain, by driving out the Muslim conquerors of the south, in the Andalusian area, by conquering the Granada region, the last stronghold of the Muslim empire, in Spain.
It was a long and hard battle, and it financially strained the Castilian coffers, but it eventually fell in 1492, and Isabella and Ferdinand finally settled Spain as a unified country, instead of individual kingdoms. Of course, the capture of Granada proved to be an even greater accomplishment, as the great explorer Christopher Columbus had to travel through the region, to eventually find America.
Forever The Iconic Power Couple – The Catholic Monarchs
It is needless to say that the union of Isabella and Ferdinand will always remain one of the most iconic moves in history. While at first, their marriage were merely for political gain, the pair remained loyal to one another, even proving every now and then that they both were in love with each other. After all, they did have three children together, and even on his deathbed, Ferdinand apologised to Isabella, who had already died more than 10 years before him, since he tried to break a promise with her, but failed.
To this day, the pair are buried in the Royal Chapel in Granada, in the place where they made their greatest achievement. Unifying Spain and returning its power to the hands of the Castilian people. In fact, you can even visit their final resting place, in Granada. Tickets are just €5. Of course, if you do visit, remember you’re entering into an active place of worship, and you’ll need to respect the rules that are in place.