84: The Squalid Drama: Succession, Madness, and the Foreign Takeover of Spain (1504-1517)

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Queen Isabel of Castile, last will, October 1504
“In accordance with what I owe and am obliged by law to do, I ordain, establish and install as universal inheritor of all my kingdoms, lands and estates and of all my possessions the most illustrious Princess Lady Juana, Archduchess of Austria, Duchess of Borgoña, my dear and most beloved first born daughter, legitimate inheritor and successor of my kingdoms, lands and estates and, that upon my death she should become queen.”

On November 26, 1504, between eleven o'clock and noon, Queen Isabel of Castile died in the castle at Medina del Campo. She had ruled for thirty years alongside her husband Fernando of Aragon, unifying Spain, conquering Granada, expelling the Jews, and launching Columbus toward the New World. She had built a diplomatic network across Europe, reformed the Church, and centralized royal power over a rebellious nobility. Yet as she took her final breath, making the sign of the cross at the words "Consummatum est," the lifetime of work she and Fernando had built together was on the verge of falling apart.

The problem was straightforward and devastating: their children kept dying.

What followed was what the historian J.H. Elliott called a "squalid drama"—a decade of intrigue, betrayal, and disputed succession that transformed Spain from an independent power into the centerpiece of a vast Habsburg empire. Isabel and Fernando had spent decades using marriage alliances to diplomatically isolate France, their traditional enemy. The irony was devastating: those same alliances would deliver their unified Spain into the hands of the foreign Habsburg dynasty they had sought merely to befriend. Their anti-French strategy became the mechanism by which Spain was subordinated to a prince who spoke no Spanish, cared nothing for Spanish interests, and would rule from Flanders with Flemish advisers.

This is the story of how a biological accident, a political conspiracy, and a convenient declaration of madness combined to place the Spanish crown on the head of Charles of Ghent—a young man Isabel herself had feared as "of another nation and other tongue."

The catastrophe started in 1497. Prince Juan, the golden heir in whom all hopes rested, died suddenly just six months after marrying Margaret of Austria. He was nineteen. Some said exhaustion—he had been enthusiastic in his marital duties. Others whispered about smallpox. His pregnant wife later gave birth to a stillborn child. Isabel's grief was profound. From that moment, chroniclers noted, she lived "without pleasure."

But the succession could pass through daughters. Isabel, the eldest surviving child, was married to King Manuel I of Portugal. When she died in childbirth in August 1498, at least her infant son Miguel survived—and Miguel represented something extraordinary. As heir to Castile, Aragon, and Portugal, the child promised to unify the entire Iberian Peninsula under one crown.

Then, on July 20, 1500, two-year-old Miguel passed away in Isabel's arms.

The succession now passed to Juana, the one child Isabel and Fernando had hoped to avoid. Juana was married to Philip of Burgundy, called "the Handsome"—a foreign prince with foreign interests and an uncomfortably warm relationship with France.

The marriage seemed wise in 1496, when Isabel and Fernando arranged a double wedding alliance with the Holy Roman Emperor Maximilian: Juana would marry Maximilian's son Philip, and Prince Juan would marry Maximilian's daughter Margaret. The goal was to strengthen ties with the Empire and further isolate France. No one expected that, within four years, a series of deaths would turn this seemingly minor alliance into the direct line of succession to the Spanish throne.


By 1500, Juana was living at the Burgundian court, and troubling reports were reaching Spain. She was obsessively attached to her husband, a man notorious for his infidelities. When Philip strayed, Juana's jealousy became intense. She lashed out at the Spanish attendants rather than confronting her husband. She showed little interest in statecraft. It was sadly observed that only "attachment" to Philip could motivate her to return to Spain.

More ominously, Philip's political stance was openly pro-French. In April 1503, he negotiated the Treaty of Lyon, aiming to return Naples to France—without Isabel and Fernando’s approval and in direct defiance of Spanish policy. Fernando immediately disavowed it. Then, in September 1504, with Isabel clearly near death, Philip joined his father, Maximilian, and Louis XII of France in an overt anti-Spanish alliance.

When Isabel and Fernando summoned the couple to Spain to be recognized as heirs, they delayed for eighteen months. When they finally arrived in early 1502, they intentionally took the land route through France, where Philip lingered at Louis XII's court through Christmas, offering tokens of vassalage to the French king. It was a calculated insult.

On May 22, 1502, the Cortes of Castile finally took their oath to Philip and Juana as heirs apparent. However, the ceremony was tense. Castilian nobles openly expressed concerns about Philip's lack of knowledge of the Spanish language and customs. They could see what was coming: a foreign king who would focus on Burgundian interests, possibly rule from Flanders, and fill his administration with Flemish advisors.

Isabel, watching her daughter and son-in-law at court, foresaw the impending disaster. When she drafted her will on October 12, 1504, she included detailed legal provisions to prevent what she could not politically stop.

Her will recognized Juana as heir, but with notably unenthusiastic language: "conforming with what I ought to do and am obliged to by law." It specified that Philip should be recognized only as King-Consort, not King in his own right. It commanded that fortified places be held "for her alone." Twice, it prohibited foreigners from receiving royal posts or ecclesiastical dignitaries—a direct attack on Philip's anticipated Flemish administration.

Most importantly, Isabel devised a contingency plan: Fernando would serve as regent if Juana "does not wish to govern or cannot understand governing" until their grandson Charles turns twenty. The dual formulation was deliberate—it covered both voluntary abdication and mental incapacity without explicitly declaring Juana incompetent.

Two weeks later, Isabel was dead. The legal trap was in place, but executing it would require something Fernando didn’t yet have: an agreement that Juana was unfit to rule.

Fernando's position after Isabel's death was precarious. For thirty years, he had been King of Castile through his marriage. Now, suddenly, he was just an administrator—and only if Juana was absent or unwilling to govern. Castilian law usually recognized a married woman's husband as regent, not her father. Philip had full legal right to assert control.

In January 1505, Fernando convened the Cortes at Toro and was recognized as governor. His argument was straightforward: he told the assembled representatives that Juana was mad.

Philip, from Flanders, immediately accused his father-in-law of fabricating the claim of madness "to color his usurpation." Both men were weaponizing claims of Juana's insanity against each other—and against Juana herself.

Fernando, aware of his weakness, made a surprising diplomatic turn. In October 1505, he signed the Treaty of Blois with France—abandoning the lifelong anti-French stance that had shaped his entire reign. To solidify the alliance, he married Germaine de Foix, the seventeen-year-old niece of Louis XII. The strategy was clear: if Germaine had a son, that son could inherit Aragon, preventing the Habsburgs from gaining Fernando's hereditary kingdom. Fernando was willing to dissolve the Union of the Crowns if it meant keeping Aragon out of Habsburg control.

But personal diplomacy could not change political realities. On April 26, 1506, Philip arrived at La Coruña with three thousand Flemish and German troops. Almost right away, the Castilian high nobility defected to him. Their reasoning was simple: they hated Fernando as both a strong ruler and a Catalan outsider who had used Isabel's authority to centralize royal power at their expense. A foreign prince focused on Flanders, and potential imperial succession would grant them the autonomy they sought. 

Fernando had no choice. On June 27, 1506, at Villafáfila, he signed an agreement surrendering all claim to govern Castile. The public treaty outlined joint rule by Fernando, Philip, and Juana. However, a secret clause revealed the heart of the conspiracy: both men agreed that Juana's "infirmities and sufferings" (which "for the sake of honour are not expressed") rendered her unable to rule. If she "should attempt to meddle in the government," both would stop her.

That same afternoon, Fernando secretly declared the treaty invalid before a notary. He signed in bad faith. But it didn't matter. Philip had won.

Or so it appeared. On September 25, 1506—just six months after his victory—Philip suddenly died in Burgos. He had caught a cold, ignored it, and within days was dead at twenty-eight. Rumors of poisoning circulated, but most evidence points to natural causes.

Fernando, upon receiving news in Naples, reportedly called it "one of the singular number" of providential acts in his lifetime.

Philip's death left Juana a pregnant widow, and what happened next has been debated for five centuries. She refused to govern, insisting that only her father would handle matters when he returned. In December 1506, she began transporting her husband’sr coffin toward Granada—fulfilling Philip's own wish to be buried beside Isabel—traveling only at night, surrounded by torches. When the procession stopped at a monastery, she allegedly prevented women from approaching the body out of jealous fear.

The image of Juana hovering over her dead husband's corpse became the defining image of her alleged madness.  But modern historians, particularly Bethany Aram and Gillian Fleming, have systematically challenged this narrative. For a complete examination of the historical debate over Juana’s “madness”, read my essay on the I Take History With My Coffee blog at itakehistory.com.

The truth is probably more complicated than just "mad" or "completely sane." Juana likely suffered from depression — hardly surprising, given that she lost her mother, was repeatedly betrayed by her husband, witnessed his sudden death, and was now pregnant and alone in a kingdom where every powerful man wanted to use her as a pawn. Her obsessive attachment to Philip, her jealousy over his infidelities, and her refusal to take part in religious observances were real. Whether these behaviors showed genuine inability to govern or were simply grief that ambitious men could exploit remains a matter of debate.

What's clear is that both Fernando and Philip saw Juana's supposed madness as politically advantageous. Fernando needed it to justify his regency. Philip needed it to sideline his wife and rule as king instead of just as a consort. The Treaty of Villafáfila shows that both men were willing to work together to declare her incompetent.

What happened next, however, was clear political imprisonment.

Fernando did not rush back to Spain after Philip's death. He stayed in Naples for nearly a year, finally returning in August 1507. The delay was a strategic move. During the power vacuum, Castile fell into chaos. Nobles besieged royal holdings, private armies reemerged, and cities fought among themselves. Cardinal Cisneros, whom Fernando had left in charge, barely managed to contain the chaos in northern Castile with troops raised from his own revenues.

When Fernando finally returned, he found Burgos Castle under siege.

Fernando had a small, disciplined army from Naples. He forced Burgos to submit, then made strategic examples: the Marquis of Priego's castle near Córdoba was destroyed; the port of Niebla was captured and sacked. Other rebels received generous pardons. Some were left alone. Fernando was pragmatic—he lacked the power to subjugate all his enemies, and he needed Castilian resources for his foreign policy.

Upon meeting her father, Juana immediately surrendered and withdrew entirely from the world. By 1509, she had become a recluse in Tordesillas, a fortress-castle on the Duero River. She stayed there until she died in 1555, forty-six years of confinement.

Fernando carefully maintained the legal fiction. He derived his authority from Juana, ruling in her name, but he rejected Cardinal Cisneros's suggestion that she be officially declared incapable. This ambiguity served his goals. Juana was Queen Proprietress, but Fernando was the acting governor. She couldn't rule, but her legitimacy supported his regency.

Fernando's final decade was marked by the debate over whether to divide or unify his inheritance. His marriage to Germaine de Foix was arranged to produce an heir who could inherit the Aragonese crown separately from that of Castile. On May 3, 1509, Germaine gave birth to a son named Juan de Aragón.

The infant passed away within hours.

"It was merely chance which prevented" the dissolution of Spanish unity, one chronicler noted. Had little Juan survived, he would definitely have become King of Aragon, splitting the crowns Isabel and Fernando had united. The personal union of Spain—formed in 1479—was kept together purely by biological accident.

Fernando kept hoping for another child until at least 1513, remaining "extremely desirous of having children, particularly sons." But no son arrived.

Meanwhile, his grandson Charles stayed in Flanders, raised by Burgundian courtiers who didn't speak Spanish. Fernando's preference increasingly shifted to his other grandson, Ferdinand, born in Spain in 1502 and raised there. A prince raised in Spain would better understand Spanish interests. Charles was an unknown factor—possibly another Philip.

By 1515, a league of nobles had formed, possibly due to suspicions that Fernando might exclude Charles from succession. Fernando negotiated an agreement: he would remain governor for life; Charles would come to Spain without troops in 1516; Prince Ferdinand would go to Flanders; and Charles would receive the wealthy Military Orders after Fernando's death.

But in late 1515, Fernando fell ill at the village of Madrigalejo while preparing an expedition against North Africa. On January 21, 1516, just two days before his death, he changed his will. It had previously left control of both Castile and Aragon to Prince Ferdinand. Now, convinced that dividing power would cause "revolutions" among the nobility, he unified everything in Charles. The decision to unify the inheritance under Charles was a pragmatic move, not driven by conviction—a recognition that the unruly Castilian nobility would exploit any division to regain their lost independence.

Fernando died on January 23, 1516. 

Cardinal Cisneros governed Castile after Fernando's death with strict authoritarian rule. He assembled a volunteer militia of thirty thousand men to prevent aristocratic attempts to seize power. It succeeded, but at a cost—his heavy-handed leadership alienated both nobles and towns, offering "a foretaste of arbitrary power" that would fuel future revolts.

Meanwhile, in Brussels, Fernando's former servants gathered at Charles's court and confirmed in their positions. Castilian aristocrats were appalled. The idea of being governed by "Flemings, Aragonese, and Jews" (many of Fernando's officials were conversos) seemed worse than anything they had faced. As one contemporary lamented, it would be "better to entrust affairs to the purest-bred Frenchman than to an Aragonese."

Charles arrived on the Asturian coast in September 1517 after weather delays. He traveled through fog and rain to Tordesillas, where, on November 4, he received his mother Juana's permission to assume royal power. The legal fiction persisted: Juana remained Queen Proprietress until her death, but Charles ruled in her name.

On November 8, 1517, Cardinal Cisneros received his dismissal letter from Charles's Flemish adviser, the Sieur de Chièvres. He died the same day at Roa near Valladolid.

The symbolism was perfect. As J.H. Elliott noted, "The Castilians had been worsted by Chièvres and his Flemings, and had seen all their forebodings confirmed. The alien Habsburg had assumed the government of Spain—and assumed it with alien ministers."

Isabel and Fernando's foreign policy was both brilliant and disastrous. Fernando achieved his immediate goals: he took back the Catalan counties of Rosselló and Cerdanya from France, gained control of Naples, and established professional diplomatic and military systems—such as resident embassies and reformed infantry—that would serve Spain throughout the 1500s.

Yet the dynastic marriages aimed at isolating France ultimately placed Spain under Habsburg control. As Elliott noted, "how much accident influenced the final outcome alongside deliberate policy." It was not only Prince Juan's death that doomed Spain to Habsburg rule — three additional unpredictable deaths made the succession unavoidable.

Spain's fate was now deeply connected to Burgundian court politics, the Netherlands trade, and Habsburg imperial ambitions. Economic interdependence strengthened dynastic ties—by mid-century, nearly half of Spain's wool exports went to the Netherlands, while the Netherlands sent a third of its exports to Spain.

The question hanging over Spain in 1517 was whether Charles's "principles of Christian universalism"—the idea of a universal Habsburg empire defending Christendom—would bring "blessing or curse." Would Spanish resources serve Spanish interests, or would Castilian gold and soldiers be used for German, Flemish, and Italian wars for Habsburg goals?

The Castilian nobility who had welcomed Philip in 1506 as relief from Fernando's rule now faced exactly what they had feared most. They had opposed Fernando as a Catalan outsider. They got Charles, who spoke no Spanish and ruled with Flemish advisers. They sought autonomy but found themselves subordinated to a vast empire. As one chronicle noted, this was "the last thing the Castilians had envisaged when they originally placed their hopes in Charles of Ghent."

Fernando died "embittered and resentful, cheated not by his opponents, all of whom he had outwitted, but by a malignant fate" that sent his masterwork to "alien descendants." His last letter to Charles, written the day before he died, stated he had worked "with soul and body for your good" and had freely chosen not to dispose of his kingdoms differently. However, Lorenzo Galíndez de Carvajal, who was there, later testified that Fernando hesitated until his final days. That Fernando hesitated tells a different story—one of reluctant acceptance rather than willing choice.

Meanwhile, Juana—the legitimate Queen of Castile—remained imprisoned at Tordesillas. She would outlive her father by thirty-nine years and witness Spain's transformation into the center of a global Habsburg empire, all while confined to dark rooms where she was forbidden even to look out the windows.

Her imprisonment, along with the deaths of her siblings and nephew, handed Spain over to a foreign dynasty that would rule for two centuries—all because Isabel and Fernando's diplomatic chess game against France had one unexpected consequence: they checkmated themselves.

The Spain that Charles of Ghent inherited in 1517 would become the center around which the entire sixteenth century revolved. Over the following decades, Spanish gold from American mines would fund wars on four simultaneous fronts: against Protestant reformers in Germany; against Ottoman expansion in the Mediterranean and central Europe; against Dutch rebels fighting for independence from Habsburg rule; and across a global empire stretching from Manila to Mexico City. The Castilian treasury—and Castilian soldiers—would bear the burden of Charles's vision of a universal Christian monarchy, draining Spain's resources to defend Habsburg dynastic interests across Europe and beyond.

To understand how this happened, we must return to Charles's origins—those Burgundian Netherlands that seemed foreign to Castilian nobles in 1517. Charles was not only King of Spain but also Duke of Burgundy, inheritor of northern Europe's wealthiest urban economy. The seventeen Low Countries—prosperous, urban, politically divided, and increasingly Protestant—became a testing ground for Habsburg ambitions. The Netherlands, more than any other territory, revealed the Habsburgs’ core dilemma: how could one dynasty rule such diverse territories in terms of language, law, religion, and interests?

Next time, we'll travel north to the Burgundian inheritance—the patchwork of provinces Philip the Handsome left to his son, where wealthy merchants challenged noble privilege, where seventeen provinces fiercely protected their ancient rights, and where the seeds of the Dutch Revolt were already beginning to grow. Before the Netherlands could rebel against Spain, we need to understand what the Netherlands really was—and why its union with Spain was doomed from the very beginning.



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