Rather than ruling a coherent kingdom, the House of Habsburg had assembled a complex federation all over Europe through marriages, conquests, and inheritance, ultimately culminating in Charles to become heir of the Holy Roman Empire as a Habsburg, the Empire of Spain through his mother Joanna, daughter of Ferdinand and Isabella, as well as ruler of the Burgundian Netherlands. Charles grew up in his holdings in the Netherlands until he became King of Spain to rule alongside his mother in 1516. He brought with him his Flemish entourage as advisors, sowing distrust between himself and local nobles and the bourgeoisie that had grown up following the Reconquista.
In the meantime, Castile erupted. It began in Toledo when royal bureaucrats arrived to remove the anti-Imperial city council with the aim of replacing them with new councilors on the king’s bankroll. Riots broke out, driving away the royalists and installing a new council elected by its own citizens. The success in Toledo spread quickly through central Spain, with city after city falling to revolution. Southern Castile, which was stocked with large garrisons on royal salaries as guards against the Moriscos (converts from Islam to Christianity), maintained its loyalty to Charles.
The revolution continued with wild ideas of establishing themselves as free city-states modeled on those in Italy and ending the monarchy. Peasants began to overthrow their local lords, declaring their freedom and looting estates. Eventually more moderate opinions won out, seeking a Castile liberated from Charles and ruled by Joanna, loyal nobles, and the popular voice. The Comuneros formed up an army and marched on Tordesillas, creating a new Cortes to be presided over by Joanna.
Joanna was called “the Mad” and had always ruled with a co-regent, first her husband, Philip the Handsome, and then her father, Ferdinand II of Aragon. During the time of her father’s tenure, he confined Joanna, the proper heir to Castile, to a convent and surrounded her with servants and advisors loyal only to him. During this time, stories of her madness began to spread, which modern historians speculate as depression, perhaps due to her confinement. She was believed to have exhumed her husband’s body and kept it with her as company in Tordesillas.
The new Cortes asked Joanna to sign an edict legitimizing their political actions, but she paused. Charles had scoffed at the revolt and sent new orders to retrieve the taxes. His regent in Spain and former tutor, Adrian of Utrecht served as General of the Reunited Inquisitions of Castile and Aragon struggled to maintain peace with new policies to win over the favor of nobles, but assassins had struck before Adrian could convince Charles of the seriousness of the Comuneros. With Charles hundreds of miles away and seemingly ignorant, Joanna’s confessors advised that she take over the country before the noble-killers gained their way.
With Joanna as queen, the Comuneros continued to grow. In the north, the royalists assembled an army at Medina de Rioseco, and a Comuneros army under Pedro Téllez-Girón marched to face them. Girón feinted a raid on nearby Villalpando, prompting the royalists to de-entrench and charge for Tordesillas. The Comuneros cut them off in a sweeping victory. Armies in the south began to question the sources of their pay, debts from the royalists stacked up, and soon defection became rampant.
Charles turned his attention to Spain too late. A similar revolt by the Germanies in Aragon occurred at the same time, but their lack of legitimacy and death of leading moderate Llorenç brought about a new alliance between the royalists and nobles there to protect their holdings from peasant uprising. Charles secured his claim in Aragon and soon after repelled an invasion by the French-backed King of Navarre to reclaim his lands seized by Charles’ grandfather Ferdinand II. While he still held eastern Spain, nothing short of war with his own mother could retake the west. Charles at last reasoned that his mother was decades older than he and simply waiting for her death would bring the lands back under his control, even if through his younger brother Ferdinand as a puppet.
Unfortunately for Charles’s plan, Joanna’s simple life loosely presiding over the Comuneros-led Cortes enabled her to live until 1555. Charles, meanwhile, became fervent about maintaining his holdings, never to let another slip away. Conquests in New Spain stayed loyal to his side, and he encouraged settlement of rich new lands in America loyal to his centralized government. He established an ongoing inquisition in the Netherlands in 1522 and personally led the violent suppression of anyone opposing him. He later installed a similar inquisition in Germany to halt the teachings of Luther and crush the Peasant’s Revolt of 1524, simultaneously weakening the power of the princes. When Henry VIII of England requested to divorce his aunt Catherine of Aragon, Charles marched on London. Throughout Charles’s rule, he would fight a two-front conflict with France and the Ottomans, establishing a centralized military bureaucracy loyal only to him.
Upon the death of Joanna, Charles was near death himself, suffering from epilepsy and gout. Rule of Castile passed to Ferdinand, who soon granted it to Charles’s son Philip, now the Holy Roman Emperor. Threats of revolt prevented Philip from uniting Castile with royalist Aragon, making it one of the most liberal pieces of the grand militaristic empire under the Hapsburgs, which ultimately unified the Catholic World in the Treaty of Joinville with France against the threat of Protestants in Northern Europe.
In reality, Adrian of Utrecht had not been assassinated. After he announced what the revolt would do to her son’s name, Joanna refused to support the Comuneros, greatly weakening their position. Pedro Téllez-Girón’s military blunder, often perceived as treachery since the royalist general was his uncle, allowed the royalists to seize Tordesillas. Charles was restored to rule after the Battle of Villalar ended the revolt in 1521 and ensured his reign by again confining his mother to rooms in the convent. Toward the end of his life, Charles abdicated his lands piecemeal.