But she did not govern.
Instead, her father and then her son exercised authority.
That is why the debate over Joanna’s mental health can never be separated completely from politics.
If Joanna was truly incapable of ruling, confinement could be presented as a response to a genuine crisis.
If her incapacity was exaggerated, however, the consequences were enormous: a reigning queen had effectively been removed from public life while male relatives governed her kingdom.
The surviving evidence does not allow the question to be reduced neatly to either extreme.
Joanna displayed behavior that contemporaries considered disturbing, and there are reasons to believe she suffered serious psychological difficulties at various stages of her life.
But acknowledging that does not mean accepting every story told about “Joanna the Mad.”
Nor does it mean that those around her were politically disinterested.
Both realities could exist simultaneously.
A vulnerable queen could suffer genuine mental distress—and powerful men could exploit, magnify or politically weaponize that vulnerability.
Tordesillas Was Not the End of the Political Danger
Confinement did not make Joanna irrelevant.
In fact, her legal status meant she could remain politically dangerous precisely because she was still queen.
That became dramatically clear during the Revolt of the Comuneros, which began in 1520 against the government of Charles.
The rebels recognized what Joanna represented.
If they could obtain the legitimate queen’s support, they might be able to claim that their actions were not rebellion against lawful monarchy at all.
Joanna therefore became potentially valuable again.
For a brief moment, the woman who had spent years politically isolated found herself at the center of a struggle over legitimacy.
But she did not provide the rebels with the authorization they needed to transform her status into a functioning alternative government.
Charles survived the revolt and consolidated his position.
Joanna returned to the strange existence that had come to define her life: legally royal, politically powerless.
And the years continued.
What Was Life Like Inside Tordesillas?
Joanna’s confinement was not a modern psychiatric hospitalization.
It was royal detention.
She lived within the palace complex at Tordesillas under supervision, and access to her was controlled.
Her youngest daughter Catherine initially shared her confinement.
The emotional consequences are difficult to reconstruct without drifting into speculation, but the basic circumstances were severe enough: Joanna had lost her husband, political independence, access to ordinary court life and, over time, much of the freedom expected even by an early modern royal woman.
Her treatment was also connected directly to the political problem she represented.
The queen could not simply be allowed to appear freely at court if her presence might become a rallying point for factions opposed to those governing in her name.
Her keepers therefore possessed enormous power over her daily existence.
Later records also describe behavior suggesting that Joanna’s mental and physical condition deteriorated significantly.
A sixteenth-century history of Emperor Charles V, preserved by the Biblioteca Virtual Miguel de Cervantes, describes her final illness in 1555 and reports letters concerning her agitation, refusal of food or treatment, and episodes of shouting. The chronicler explicitly regarded her as mentally impaired.
That evidence should not simply be dismissed as propaganda.
But neither can it retroactively prove every allegation made about Joanna half a century earlier.