The reign of those known as Reyes Catholicons went down in history for two main reasons: the discovery of America and the Recon quest of the peninsular territories to the Arabs. This recon quest went much further, since until now, Spain was a set of different independent kingdoms that under the reign of Isabel and Fernando were united under one same crown, at least legally. Queen Juana, heiress of the kingdom of Castile, suffered mental problems and was separated first by her husband and then by her father, all her life in Tordesillas. His son was in charge of inheriting a poisoned candy, a country that was not as close as it seemed and that he was certainly not the person to stabilize, at least a priori.
To make this affirmation I rely on all the problems Carlos I had to get recognized as heir to the throne. One of those reasons is that it showed little knowledge about the country and its customs, but what is worse, did not show a real interest in knowing it. He was educated in the court of Hapsburg in contrast to his brother Fernando, who grew up with his maternal grandfather in Spain and was considered the ideal person to inherit the throne because he was one of his own. It did not help at all that when the young monarch arrived in Spain he would not be able to speak his language fluently and would endeavor to be accompanied by nobles and Flemish advisors who felt superior to the Spaniards and were arrogant.
There was also the fear that the foreign king decided to expel the riches of the Spanish kingdom taking them to his court of Hapsburg, reason why was forced to sign an agreement by which it could not take anything of value of the country. Obviously, he was considered someone from the outside who did not deserve confidence and who could only expect tricks and trickery to steal gold from America.
Last but not least, the injustices committed against his mother, Juana I, were known by all the people who professed great affection for their “crazy” queen. Juana had first been despised by her husband, who did not hesitate to be often unfaithful, a normal thing at the time since it was a political marriage. But she, really in love with young Felipe, suffered greatly for that reason and her love story filled the town. Later, her father declared her officially mentally ill to detain her and remove her from her rights to the throne, and her son, although he reigned with the mother officially, also ignored her and kept her in her confinement. For this reason he was forced to give his word that the mother would receive a better treatment than he had among the conditions that he should have accepted to obtain the kingdom of Aragon.
Little respectful of Spanish customs, contemptuous of the nobility of the country and clearly considered a bad son, Carlos I had all the ballots to be hated by his people. Poorly advised from the outset by his advisers, he did not know how to start his career in Spain with a good foot, which almost made his brother’s supporters succeed in turning him into an heir, which was also the wish of his grandfather Fernando. Only great diplomatic work and long negotiations managed to put on his head the one that was the first crown that united all the kingdoms of Spain in the same person.