The amber light of the setting sun filtered through the stained-glass windows of the Alcázar of Madrid, staining the pale, elongated face of King Philip IV with a hue of melancholy. The year was 1649, and the monarch of the House of Austria stood in the silence of his chamber, observing the portrait of his first wife, Isabella of Bourbon, who had passed away five years prior. Known as the Planet King, revered for his patronage of the arts, he now carried the crushing weight of an empire in decline and the desperate, pressing need to secure the succession of the Spanish throne.
Majesty, a voice interrupted his thoughts. The Count-Duke of Olivares had entered the room with the silence of a shadow. The emissaries have returned from Vienna with the Emperor’s response.
Philip IV nodded slowly, refusing to tear his gaze from the painted eyes of his late wife. And well? What does my cousin Ferdinand say?
The Emperor has given his blessing for the marriage, the Count-Duke reported, his voice low and formal. Archduchess Mariana will be ready to travel to Spain as soon as your Majesty deems it appropriate.
A heavy silence settled between the two men. Mariana of Austria was the daughter of Emperor Ferdinand III of Germany, who was, in turn, the brother of Philip IV. The young archduchess was, therefore, the king’s own niece.
How old is my niece now? Philip asked, though he knew the answer perfectly well.
She will turn fourteen this coming December, Majesty.
Philip IV rose slowly from his seat and walked toward the window. Madrid stretched out beneath his gaze, oblivious to the political webs being spun in the high spheres of power. The marriage to his young niece was not a matter of affection; it was a matter of state. Endogamy within the European royal houses was not a novelty, but a common, entrenched practice intended to preserve power and solidify alliances.
Prepare everything to receive her, he finally ordered. The wedding will be celebrated as soon as she arrives in Spain.
Meanwhile, in the Imperial Palace of Vienna, young Mariana received the news of her imminent marriage with a mixture of astonishment and resignation. Educated from the cradle to serve the interests of her family, she knew that her destiny had been sealed long before she had the capacity to understand it.
Will I marry my uncle? she asked her lady-in-waiting, the Countess Bon Harrach, while the older woman brushed her long, chestnut hair.
With the King of Spain, the Countess corrected her firmly. It is a great honor for you, Highness. You shall be the Queen of the most vast empire in the world.
Mariana fell silent. At almost fourteen, she barely knew her uncle Philip, whom she had only seen in the portraits that adorned the palace walls. She knew he was much older than she was and that he had been married to Isabella of Bourbon, with whom he had fathered several children, though only the Infanta Maria Theresa, aged ten, and Prince Baltasar Carlos had survived infancy. However, the prince had passed away three years prior, leaving the Spanish Crown without a male heir.
And if I cannot give him a son? Mariana whispered, voicing her deepest fear.
The Countess stopped brushing and looked at the young archduchess with severity. You must not think of that, Highness. God will bless your union with many sons. I am sure of it.
The following months passed in a whirlwind of preparations. On October 7, 1649, Mariana of Austria was married by proxy to Philip IV, represented by Archduke Leopold William of Austria. Then began the long, exhausting journey toward Spain, crossing through Italy and finally embarking at the port of Final Ligure. The young queen spent Christmas in Milan, and it was not until April 4, 1650, that she finally landed in Denia, in the Kingdom of Valencia.
There, she was received with all the honors by the nobles and dignitaries sent by King Philip. Impatient to meet his young bride, the King traveled incognito to Navalcarnero, where he finally met Mariana. On October 7, the wedding was celebrated in the small Madrid locality, an intimate ceremony that contrasted with the immense political importance of the union.
Mariana’s first impression of her husband and uncle was that of a man aged prematurely, marked by the characteristic Habsburg prognathism—a prominent lower jaw—and a tired gaze that reflected the weight of three decades of turbulent reign. For his part, Philip IV found in his niece and new wife a shy and not particularly beautiful young woman, but one possessing the quiet determination typical of the House of Austria.
You are very changed since the last time I saw you, Philip remarked during the nuptial dinner, though in truth, he barely remembered the girl he had seen briefly years before.
I was only six years old then, Majesty, Mariana replied, maintaining her composure despite her nervousness.
Philip corrected her with a slight smile, Now, you are my wife, not just another courtier.
After the wedding, the royal couple headed to the Alcázar of Madrid, where their life together began. The age gap of thirty years and their close kinship were not seen as obstacles in an era when royal marriages were arranged for political reasons, not for love. However, the shadow of incest, even if it was not spoken of by that name, loomed over the union, manifesting in the deep concerns regarding the offspring that might arise from such a bond.
The first years of the marriage were difficult. In 1651, Mariana gave birth to her first daughter, the Infanta Margaret Theresa, who survived infancy and would eventually become Empress by marrying her uncle, Emperor Leopold I, following the family’s endogamic tradition. However, the subsequent pregnancies ended in tragedy. The Infanta Maria Ambrosia, born in 1655, passed away after fifteen days, and another son was stillborn in 1657.
The pressure on the young queen increased with every failure. The court whispered about the possibility that consanguinity was affecting the royal lineage. The doctors of the era, however, did not directly relate these problems to the close kinship of the parents, attributing them instead to divine design or the constitutional weakness of the mother.
In 1658, after several years of disappointments, the long-awaited male heir was born: Prince Philip Prosper. The jubilation in the court was immense, and great celebrations were organized throughout the kingdom. Philip IV, already fifty-three, seemed to rejuvenate at the prospect of finally having a successor.
God has heard our prayers, the King declared during the prince’s baptism in the royal chapel. Spain has an heir.
However, the joy lasted only a short time. The little prince showed fragile health from the very beginning. Pale and sickly, he suffered from frequent convulsions that kept the court in constant suspense. The royal physicians, baffled, applied remedies that we would today consider barbaric: bloodlettings, purges, and concoctions of dubious efficacy that only succeeded in further weakening the child.
In 1661, another infant, Ferdinand Thomas, was born, but he died before reaching his first year. The situation became desperate for the Spanish monarchy, and rumors about the curse hanging over the royal family intensified. Some of the more superstitious courtiers linked these misfortunes to the close kinship of the monarchs, though such comments never reached the ears of the royalty.
The final tragedy arrived in November 1661, when Prince Philip Prosper passed away at four years of age, plunging the court into mourning and despair. Philip IV, devastated by the loss, locked himself in his chambers for days, refusing to receive anyone, including the queen, who in turn suffered the pain of loss in solitude.
Yet, destiny had one last card to play. On November 6, 1661, just five days after the death of Philip Prosper, Queen Mariana gave birth to another boy, who was baptized as Charles. No one could have imagined then that the boy born under the sign of tragedy would be known to history as Charles II, The Bewitched, the last of the Spanish Habsburgs, and that in him would manifest, in a dramatic fashion, the consequences of generations of endogamy.
The morning of November 6, 1661, dawned grey and rainy in Madrid. At the Royal Alcázar, while the courtiers still wore mourning for the death of Prince Philip Prosper, the weak and broken cry of a newborn was heard. It was Charles, the new heir to the Spanish throne, who arrived in the world under somber circumstances.
From the very first moment, the doctors and midwives noticed that something was not right with the infant. His head was disproportionately large for his small, fragile body, and he presented difficulties in nursing. Dr. Olivares, the queen’s personal physician, observed the facial characteristics of the newborn with concern. The prominent jaw, typical of the Habsburgs, manifested in him in an exaggerated way, hindering his suction and, subsequently, his ability to chew and speak.
Majesty, the doctor said with caution as he presented the little one to Philip IV, The prince will require special care.
The King contemplated his son with a mixture of relief and concern. At his age, he was aware that this was possibly his last chance to have a male heir. Despite the child’s evident weakness, Philip clung to hope.
He will live, he declared with firmness. He must live. He is the future of Spain and of our dynasty.
The first years of Prince Charles’s life were marked by a succession of illnesses and crises that kept the court in constant alarm. He did not learn to speak until he was four, and he did not walk until he was five. His physical and intellectual development was notoriously slower than that of other children his age.
The prince’s education became a challenge for his tutors, who had to adapt their methods to the heir’s limitations.
I cannot get him to retain the most basic lessons, lamented his tutor, Antonio de la Cerda, in a private conversation with Queen Mariana. His mind seems to wander constantly, and when I try to maintain his attention, he becomes irritated or falls asleep.
The queen, who had assumed the regency of the kingdom after the death of Philip IV in 1665, listened to these reports with increasing anguish. At thirty, Mariana of Austria found herself governing an empire in decline, with a son of precarious health as her only hope for dynastic continuity.
Continue with your efforts, she would invariably order. The prince must be prepared to govern when the time comes.
But in the privacy of her chambers, Mariana wept and prayed for her son, conscious that in him were manifesting, in a cruel way, the effects of generations of consanguineous marriages. Endogamy had been a deliberate policy of the Habsburgs to maintain power and prevent the dispersion of the family patrimony, summarized in the famous phrase attributed to Maximilian I: Bella gerant alii, tu felix Austria nube—”Let others wage war, you, happy Austria, marry.”
The coefficient of consanguinity of Charles II—a measure indicating the probability that an individual receives two copies of the same gene from a common ancestor—was exceptionally high, comparable to that which would result from a union between siblings. This was because his parents, although uncle and niece, shared common ancestors through multiple genealogical lines, the result of generations of marriages between relatives.
As Charles grew, his health problems became more evident. He suffered from rickets, which caused great weakness in his legs; he endured recurrent episodes of fever and intestinal discomfort; and he showed signs of what we might today identify as a cognitive delay. His lower jaw was so prominent that it prevented him from completely closing his mouth, which made it difficult for him to properly chew food and articulate words clearly.
The prince cannot eat meat, Dr. Olivares informed in one of his periodic reports. His teeth do not fit well, and I fear he might choke if he attempts to chew solid foods.
To these ills were added occasional epileptic crises that terrorized the court. During these episodes, the prince suffered violent convulsions that left him exhausted and confused. The doctors, limited by the knowledge of the time, resorted to ineffective remedies like bloodletting, which only served to further weaken the young heir.
In the palace, rumors circulated about the nature of the prince’s illness. Some courtiers, influenced by the superstitions of the time, spoke in secret of a curse or a spell. These rumors reached the ears of the royal confessor, who suggested the possibility that the prince was bewitched, giving rise to the nickname by which he would be known in history: “The Bewitched.”
It is the work of the devil, some whispered.
A divine punishment for the sins of the royal family, others maintained, alluding veiledly to the consanguineous marriage of his parents.
Meanwhile, the regent, Mariana of Austria, governed with a firm hand, leaning on her confessor, the Austrian Jesuit Juan Everardo Nithard, and subsequently on Fernando de Valenzuela, a nobleman of modest origin who ascended meteorically in the court thanks to the queen’s favor. These favorites, with their political power, generated deep rejection among the Spanish high nobility, especially in Don Juan José of Austria, the illegitimate son of Philip IV and half-brother to Charles II.
As Charles approached the age of majority, set at fourteen, the noble factions intensified their struggles for power. Don Juan José of Austria, supported by a large part of the aristocracy, pressured to remove the Queen Mother and her favorites from the government. In 1677, after a palace coup, he managed to distance Mariana from the Court and assume effective control of the government.
Although Charles II had formally been declared of age, the young king, at sixteen, was barely a decorative figure, manipulated by the different factions that fought for power. His education had been deficient due to his limitations, and he showed little interest or capacity for state affairs. The descriptions of foreign ambassadors in the Spanish court paint a desolate portrait of the monarch.
His Catholic Majesty is short in stature, quite robust; he is not deformed but poorly built, the French ambassador wrote in 1689. He is ugly of face, has a long neck, a long face, and it is as if it were bent toward his chin. His mouth is always open, but his lips are so characteristic of the House of Austria that they cover his upper teeth. His body is as weak as his mind. From time to time, he gives signs of intelligence, memory, and a certain vivacity, but not now, for he generally seems stupid and indifferent, and nothing can be achieved from him except by nodding or repeating the words he is told.
Despite his physical and mental weakness, the question of Charles II’s marriage became a priority matter of state. The continuity of the dynasty depended on the King’s ability to father an heir. In 1679, at eighteen, Charles married Marie Louise of Orléans, niece of Louis XIV of France, in an attempt to improve relations with the powerful neighbor. The seventeen-year-old queen arrived at the Spanish court with apprehension. The rumors about the precarious health and appearance of the King had reached France, but the reality she found exceeded her fears.
However, Marie Louise tried to fulfill her duty, although it soon became clear that the marriage did not produce the expected fruits. The pressures on the royal couple to conceive an heir were constant. The doctors prescribed all kinds of remedies to increase fertility, from special diets to amulets and prayers. Processions and novenas were organized throughout the kingdom to ask God for a prince for Spain. But the years passed, and the queen’s womb remained sterile.
Rumors about the King’s impotence began to circulate through the European courts. It was speculated that Charles II, due to his physical problems derived from consanguinity, was incapable of properly consummating the marriage. The situation became a matter of international interest, as the future balance of power in Europe depended on the reproductive capacity of the last Spanish Habsburg.
In 1689, after ten years of marriage without children, Marie Louise of Orléans died suddenly at the age of twenty-seven, possibly from appendicitis. The Queen’s death plunged Charles into a deep depression, for despite the circumstances, he had developed a sincere affection for his wife.
The need for an heir, however, did not allow for long periods of mourning. Barely a few months after Marie Louise’s death, a new marriage was arranged for Charles II, this time with Maria Anna of Neuburg, daughter of the Elector Palatine. The choice responded to strategic interests, as the goal was to strengthen the alliance with the Empire and counteract French influence.
Maria Anna of Neuburg arrived in Spain in 1690 with the difficult mission of giving an heir to the throne. Unlike her predecessor, the new queen was an ambitious and dominant woman who soon formed her own faction in the court and exerted a strong influence over her weak husband. However, despite all efforts, this second marriage also resulted in sterility.
As Charles II’s health deteriorated and it became clear that he would not have descendants, the European powers began to prepare for the partitioning of the Spanish Empire. France, Austria, England, and the United Provinces negotiated secret partition treaties, anticipating the death of the last Spanish Habsburg.
The King, conscious in his moments of clarity of the tragedy that this represented for his dynasty and for Spain, lived tormented by his inability to fulfill his main duty: providing an heir to the throne.
This is what remains of Emperor Charles V, he lamented, according to the chronicles, referring to his illustrious ancestor and the contrast with his own weakness.
The last years of Charles II were an ordeal of physical and mental suffering. His health, precarious since birth, deteriorated rapidly. He suffered constant pain, recurrent fevers, and periods of mental confusion. The doctors, powerless, applied increasingly desperate and extravagant remedies.
In 1698, the King’s health worsened dramatically to the point that his life was feared for. The succession crisis became imminent, and the intrigues at court intensified. The two main candidacies to inherit the throne were that of Archduke Charles of Austria, supported by Queen Maria Anna of Neuburg and the Austrian faction, and that of Philip of Anjou, grandson of Louis XIV, promoted by Cardinal Portocarrero and the supporters of France.
Against all odds, Charles II survived this crisis but remained even more weakened. In the following two years, his deterioration was constant, alternating periods of apparent improvement with brutal relapses. Finally, on November 1, 1700, the last Spanish Habsburg passed away at thirty-nine years of age, after a reign of thirty-five years marked by decadence, military defeats, and the loss of international influence.
In his testament, signed shortly before his death, Charles II named Philip of Anjou as his heir, a decision that would trigger the War of the Spanish Succession (1701–1714), an international conflict that redefined the political map of Europe and marked the final end of Spanish hegemony. The death of Charles II also represented the end of a dynasty that had ruled Spain for almost two centuries: the Habsburgs, who had arrived on the Spanish throne with Charles I (Charles V of the Holy Roman Empire) in 1516, disappeared from Spanish history, victims in large measure of their own endogamic marriage policy.
The tragic figure of Charles II remained in the collective memory as the symbol of Spanish decadence and as an example of the dire consequences of dynastic endogamy. His life, marked by physical suffering and political manipulation, represents one of the darkest chapters in the history of the Spanish monarchy.
In the summer of 1698, while King Charles II fought for his life in the Alcázar of Madrid, a secret meeting took place in the Buen Retiro Palace. There, away from prying eyes, Cardinal Portocarrero, Archbishop of Toledo and member of the Council of State, met with the French ambassador, the Marquis of Harcourt, and the royal physician, Dr. Jerónimo de la Parra.
His Majesty will not live much longer, the doctor stated in a low voice, as if he feared the walls might hear his words. The last episodes have weakened his body beyond imagination. It is a miracle that he is still alive.
Cardinal Portocarrero, a corpulent man with a stern face, nodded gravely. In his years, he had served the Spanish Crown for decades and had been a witness to the progressive decadence of the monarchy.
And the question of the succession? asked the French ambassador, going directly to the matter that worried all the European courts.
The King has not made a definitive decision, Portocarrero replied. The Queen presses incessantly in favor of the Austrian candidate, but many of us consider that the French option would be more beneficial for Spain.
The succession question was the hottest topic in European politics. Charles II, the last representative of the Spanish Habsburg dynasty, had not managed to father offspring in either of his two marriages. The extinction of the male line of the Spanish Austrias was imminent, and the main powers prepared to divide the vast Spanish Empire, which still included territories in Europe, America, Asia, and Africa.
Have you considered the King’s problems? Harcourt asked with caution. In Paris, rumors circulate about his mental capacity to make a decision of such magnitude.
The physician and the Cardinal exchanged a significant look. Charles II’s health problems, both physical and mental, were well known but constituted a taboo subject in the Spanish court. The dignity of the monarchy demanded maintaining a conspiracy of silence about the true nature of the King’s ailments.
His Majesty has moments of perfect clarity, Dr. Parra finally replied. In those moments, he is fully capable of understanding the importance of his decision for the future of Spain.
What none of those present mentioned openly was the underlying cause of the King’s problems: generations of consanguineous marriages that had culminated in the union of Philip IV with his niece, Mariana of Austria, the parents of Charles II. This marriage policy, intended to keep power within the family and avoid the dispersion of the patrimony, had produced devastating effects in the last generation.
While the powerful conspired about the future of the kingdom, in the royal chambers, Charles II suffered a new crisis. Surrounded by powerless physicians and terrified courtiers, the monarch experienced violent convulsions that shook his weak and deformed body.
He is possessed! shouted one of the gentlemen of the chamber, expressing the superstitious belief that many harbored about the nature of the King’s illness.
Silence! ordered Dr. Cabriada, another of the royal physicians. They are not demons, but a disease of the brain. Bring cold compresses and prepare a bloodletting.
Bloodlettings, purges, and cauterizations were customary treatments in the medicine of the time, still based on Galen’s theory of humors. However, these methods, far from helping the patient, usually weakened him further, especially in the case of an individual as fragile as Charles II.
When the crisis subsided, the King remained plunged into a deep lethargy, watched over without respite by his doctors. The news of his partial recovery spread like wildfire through the palace, reaching the ears of Queen Maria Anna of Neuburg, who went immediately to her husband’s chambers.
Maria Anna of Neuburg, second wife of Charles II, was a woman of imposing bearing, strong character, and boundless political ambition. Since her arrival in Spain in 1690, she had woven her own faction in the court and exerted considerable influence over her weak husband. Her primary political goal was to secure the succession for the House of Austria, specifically for her nephew, Archduke Charles.
How is he? asked the Queen upon entering the royal chamber.
Stable for the moment, Majesty, responded Dr. Cabriada with a bow. But we must be prepared for new crises.
The Queen approached the bed where her husband lay. Despite being only thirty-seven years old, Charles II appeared much older. His elongated face, with the characteristic prominent jaw of the Habsburgs carried to the extreme, showed signs of suffering even in sleep. His breathing was labored, and from time to time, a spasm shook his body.
Maria Anna contemplated her husband with a mixture of compassion and frustration. She had arrived in Spain with the mission of giving an heir to the throne, but it soon became clear that Charles II, just as with his first wife, was incapable of procreating. The rumors about his impotence were increasingly difficult to silence.
Leave us alone, the Queen ordered the physicians and courtiers, who withdrew discreetly.
Once alone with her unconscious husband, Maria Anna allowed herself a moment of weakness. Why, Charles? she whispered. Why can we not have a son to ensure the future of your kingdom?
The question of Charles II’s impotence was a delicate and complex subject. The doctors of the era lacked the necessary knowledge to correctly diagnose the problem. The explanations oscillated between the medical, the superstitious, and the political. Some practitioners attributed the lack of descendants to physical problems derived from the King’s general weakness. Others suggested that it was a spell or a curse, a theory that gained strength when exorcisms became part of the King’s medical treatment.
In the court, however, many suspected that the real cause was the extreme endogamy of the royal family, though no one dared to express it openly.
Charles II awoke slowly and found his wife sitting by his side. His eyes, sunken in their sockets, showed a flash of recognition.
Maria Anna, he murmured with difficulty, his voice barely audible.
I am here, my lord, she replied, taking his hand. You must rest and recover your strength.
I have had visions, said the King with effort. I saw my ancestors. They looked at me with disappointment. I am the end of the dynasty. The last of the Spanish Austrias.
The Queen squeezed his hand tighter. Do not speak like that. You will recover, and with God’s help, you will have an heir.
But both knew that this was almost impossible. After almost ten years of marriage without descendants, the hopes that Charles II could father a son were practically nil. The question now was who would inherit the vast Spanish Empire.
Meanwhile, in the salons and hallways of the Alcázar, the intrigues continued. The Spanish court was divided into two main factions: the Austrian, led by Queen Maria Anna of Neuburg, who supported the candidacy of Archduke Charles of Austria; and the French, led by Cardinal Portocarrero, who favored Philip of Anjou, grandson of Louis XIV. In the center of these intrigues was the Count of Oropesa, President of the Council of Castile, who tried to maintain a difficult balance between the different factions while attempting to implement administrative and economic reforms that would alleviate the crisis the kingdom was going through.
The situation is unsustainable, Oropesa commented to the Duke of Montalto during one of their private meetings. The treasury is exhausted, the harvests have been bad for the third year in a row, and the people suffer. Meanwhile, the court is consumed in power struggles for the succession.
And what does his Majesty think? asked Montalto.
Oropesa made an evasive gesture. The King is indecisive. His health does not allow him to concentrate on these matters for long, and he is vulnerable to the influence of those around him, especially the Queen.
What Oropesa did not mention was the mental deterioration of Charles II, which manifested in episodes of confusion, paranoia, and erratic behavior. In his worst moments, the King believed himself to be bewitched or possessed and submitted to exorcisms performed by the Inquisitor General, Fray Tomás de Rocabertí. These rituals, which combined religious elements with practices close to superstition, reflected the confusion of the era between mental illness and demonic possession. For many courtiers, the supernatural explanation was more acceptable than recognizing the degeneration produced by dynastic endogamy.
They say that during the last exorcism, his Majesty spoke in strange tongues and vomited objects impossible to digest, murmured the Duchess of Terranova to a group of court ladies.
I have heard that they found wax dolls with his effigy in the palace basements, added another lady, crossing herself. Witchcraft, without a doubt.
These rumors, far from being limited to the Spanish court, spread through all the European capitals. Foreign ambassadors sent detailed reports about the King’s health and the succession intrigues, conscious that the death of Charles II without a direct heir would trigger a reconfiguration of the European political map.
In Versailles, Louis XIV received these reports with interest. The Sun King, at sixty, was the most powerful monarch in Europe and saw the Spanish crisis as an opportunity to extend French influence.
How long do the doctors give him? he asked his Minister of Foreign Affairs, Colbert.
It is difficult to say, Majesty. He has survived crises that seemed fatal, but each new relapse leaves him weaker. I do not believe he will live more than two or three years.
Louis XIV nodded pensively. And meanwhile, we must secure our interests. Continue negotiations with England and the United Provinces for the partition treaty, but keep the channels with Madrid open. If Charles II’s testament finally favors my grandson Philip, we will be in an advantageous position.
In Vienna, the situation was followed with equal attention by Emperor Leopold I, cousin of Charles II and head of the Austrian branch of the Habsburgs. For him, the extinction of the Spanish line of the family was a dynastic tragedy but also an opportunity to reunify the domains that had been separated since the abdication of Charles V in 1556.
Our right is indisputable, Leopold declared to his advisors. The Spanish domains belong by legitimate right to our house, and we will assert that right by arms if necessary.
While the European powers prepared for the partitioning of the Spanish Empire, in Madrid, Charles II’s health experienced constant fluctuations. After the grave crisis of 1698, the King had regained enough strength to reappear in public on marked occasions, but his emaciated appearance and erratic behavior fueled rumors about his mental deterioration.
In September 1699, Charles II suffered a new crisis that nearly ended his life. For days, the court prepared for the worst, while foreign ambassadors sent urgent dispatches to their governments. However, once again, the King recovered against all odds. This partial recovery allowed Charles II to face the question he had avoided for years: the succession to the throne.
Pressed by the different court factions and conscious of his historical responsibility, the monarch began to seriously consider his options. Cardinal Portocarrero, who had gained influence over the King thanks to his role as a spiritual advisor, argued energetically for the French option. His arguments were based on practical considerations: France was the strongest power in Europe, and only its support could guarantee the territorial integrity of the Spanish Empire.
Majesty, the Cardinal said during one of his private audiences, you must think of the good of your kingdoms and subjects. The choice of the Duke of Anjou would guarantee the protection of Louis XIV and would avoid the dismemberment of your domains.
On the other hand, Queen Maria Anna and her supporters defended the candidacy of Archduke Charles of Austria, arguing the importance of maintaining dynastic continuity and warning about the danger of Spain becoming a satellite of France.
Do you perhaps want everything your ancestors built to fall into French hands? asked the Queen in her moments of intimacy with the King. Your duty is to maintain the legacy of the House of Austria.
Trapped between these contradictory pressures, Charles II sought counsel in diverse instances. He consulted Pope Innocent XII, who, according to some sources, leaned toward the French solution. He also asked for an opinion from the Council of State, where positions were divided, and from prominent jurists who analyzed the succession rights of the different candidates.
As his health worsened throughout the year 1700, Charles II found himself forced to make a decision. On October 3, barely a month before his death, he signed his final testament, in which he named Philip of Anjou, grandson of Louis XIV, as universal heir, with the condition that he renounce his rights to the French throne to avoid the union of the two crowns.
This testament, which surprised many observers who expected a decision favorable to the House of Austria, was the result of complex negotiations and pressures, as well as the King’s conviction that only French support could maintain the integrity of the Spanish Empire.
On November 1, 1700, the feast of All Saints, Charles II passed away in the Alcázar of Madrid after a long agony. He was thirty-nine years old and had reigned for thirty-five, although effective power had almost always been in the hands of regents, favorites, or court factions. His body, weakened by decades of diseases and counterproductive treatments, was embalmed according to the royal protocol and exposed in the funeral chapel.
Witnesses described the corpse as “as small as that of a child.” The autopsy performed by the royal physicians revealed multiple internal anomalies, although the official report was deliberately vague about the details, in a final act of the conspiracy of silence that had surrounded the King’s health during his whole life.
With the death of Charles II, the Spanish branch of the House of Habsburg, which had ruled the country since the arrival of Charles I in 1516, was extinguished. The testamentary decision of the last Spanish Habsburg did not avoid international conflict. The War of the Spanish Succession (1701–1714) pitted the main European powers against one another and redefined the political map of the continent. Philip of Anjou, who reigned as Philip V, became the first Spanish Bourbon, starting a new dynasty that continues today.
However, the price was high. The Treaties of Utrecht (1713) and Rastatt (1714), which put an end to the war, meant the loss of the European territories of the Hispanic monarchy: Flanders, Milan, Naples, Sicily, and Sardinia, and the start of British hegemony in the Mediterranean with the cession of Gibraltar and Menorca.
The tragic history of Charles II remained as a somber reminder of the dangers of dynastic endogamy. His case, studied subsequently by physicians and historians, reveals how the Habsburgs’ marriage policy, designed to maintain power and patrimony within the family, ended up causing the biological extinction of the dynasty in its Spanish branch.
On a freezing January morning in 1701, the Duke of Anjou, now Philip V of Spain, crossed the Gallic border at Irun to take possession of the throne he had inherited. At seventeen, the young Bourbon was the antithesis of his predecessor: tall, athletic, of healthy complexion, although with an introverted personality and a tendency toward melancholy that would accentuate over the years.
There are no longer Pyrenees, Louis XIV had supposedly exclaimed when seeing off his grandson, manifesting his satisfaction with the dynastic continuity that placed the Bourbons on both the French and Spanish thrones. However, the new monarch would find a country plunged into a deep economic, social, and political crisis, weakened by decades of poor government and the recent succession crisis.
The grandees of Spain, accustomed to the weakness of Charles II, observed the young French monarch and his advisors with suspicion, fearful of losing their privileges and influence. Among this nobility stood out the Duke of Medinaceli, descendant of the House of de la Cerda and one of the most powerful aristocrats in the kingdom. In his vast palaces in Madrid and Andalusia, valuable family archives were kept that documented centuries of Spanish history, including detailed records about the marriage policy of the House of Austria.
Astonishing, commented the Duke to his secretary while they reviewed old bundles of papers in the library of his Madrid palace. Our Habsburg kings married repeatedly with their own relatives, ignoring all the warnings about the risks of such unions.
The secretary, an educated man named Antonio de Mendoza, nodded gravely. The archives show that there were voices that warned about the dangers. Dr. Luis Mercado, physician to Philip II, wrote a treatise where he mentioned, although in a veiled way, the risks of consanguinity.
And yet, Medinaceli continued, those warnings were ignored generation after generation. The result was Charles II, in whom all the defects accumulated over centuries were manifested.
Modern studies confirm the Duke’s observations. The coefficient of consanguinity of Charles II was exceptionally high, 0.254, comparable to that which would result from the union between siblings (0.25). This means that, due to the multiple marriages between relatives in his genealogical tree, approximately 25% of his genes were identical by descent. This extreme consanguinity explains many of the physical and mental problems of the last Spanish Habsburg: the prominent prognathism (protruding lower jaw), the general weakness, the respiratory difficulties, the infertility, and possibly also his neurological and cognitive problems.
The marriage policy of the Austrias was not exceptional in itself. Endogamy was common among European royal houses as a means to maintain power and family alliances. But the House of Austria took it to unprecedented extremes. Charles II had only 32 great-great-great-great-grandparents instead of the 64 that a person without common ancestors would have, and many of them appeared multiple times in his genealogical tree.
In the new reign, the question of dynastic marriages continued to be crucial. Philip V, widowed after the early death of his first wife, Marie Louise of Savoy, entered into a second marriage with Elisabeth Farnese, Princess of Parma, in a marriage arranged by the Princess of the Ursins, lady-in-waiting to the King’s first wife and an influential figure in the court.
Elisabeth Farnese turned out to be a woman of strong character and great political ambition. Unlike the sweet Marie Louise, Elisabeth quickly dominated her melancholic husband and exerted a determining influence on Spanish politics for decades.
The Queen is extraordinarily astute, commented the French ambassador, the Duke of Saint-Simon, in one of his dispatches. She has managed to isolate the King from everyone except herself, and she effectively governs the kingdom while he sinks more and more into melancholy.
Philip V, indeed, suffered recurrent episodes of severe depression that sometimes incapacitated him for months. During these periods, he refused to leave his chambers, neglected his personal hygiene, and displayed erratic behaviors such as inverting day and night or wearing the same clothes for weeks. These episodes, which we could today diagnose as bipolar disorder, posed disturbing parallels with the mental problems of Charles II, although their origins were different. While the problems of the last Habsburg were probably related to consanguinity, those of Philip V seemed to have a hereditary origin in the Bourbon line, since his grandfather Louis XIV had suffered similar episodes in his youth.
The new dynasty, however, was conscious of the dangers of extreme endogamy and sought to avoid marriages between close relatives that had characterized the Austrias. The children of Philip V married princesses from diverse European royal houses, expanding the genetic base of the Spanish royal family. This more prudent policy bore fruit. The Spanish Bourbons, unlike their Habsburg predecessors, did not experience the extreme physical problems that had affected Charles II.
Nevertheless, mental disorders continued to manifest in the family. Philip V’s son, Ferdinand VI, suffered episodes of madness similar to his father’s, and his half-brother, Charles III, although mentally stable, displayed obsessive behaviors and rigid rituals that we would today associate with obsessive-compulsive disorder.
Meanwhile, the memory of Charles II and the Spanish Austrias gradually faded. The Bourbons promoted a new aesthetic and new symbols that consciously broke with the Habsburg past. The elongated face and the prominent jaw of the Austrias, immortalized in the portraits of Velázquez, were replaced by the more harmonious physiognomy of the Bourbons in the canvases of painters like Jean Ranc or Louis-Michel van Loo.
However, in certain noble circles and among some intellectuals, the memory of the decadence of the Austrias and its causes remained alive. The case of Charles II became a paradigmatic example of the dangers of endogamy, cited in medical treatises and historical works. In 1761, during the reign of Charles III, the enlightened physician Andrés Piquer published his discourse on the illness of the King, “Our Lord Ferdinand VI,” where he analyzed the mental disorders of the late monarch. Although Piquer was cautious in his conclusions, he veiledly suggested hereditary influence in the mental illnesses of the Spanish Bourbons, establishing an implicit parallel with the degeneration of the last Austrias.
As the 18th century advanced and the enlightened ideas spread throughout Europe, the criticism of the endogamic practices of the royal houses became more explicit. The philosophers and scientists of the Enlightenment, influenced by rationalism and empiricism, questioned aristocratic traditions and advocated for a more scientific approach to matters like marriage and reproduction.
In Spain, intellectuals like Gaspar Melchor de Jovellanos or Father Feijóo incorporated these ideas into their writings, although always with the necessary caution to avoid problems with censorship and the Inquisition, which remained active, although with reduced powers.
Nature does not distinguish between the blood of kings and that of shepherds, wrote Feijóo in his “Universal Critical Theater,” an apparently innocuous statement but one that contained an implicit criticism of the idea of the innate superiority of the aristocracy.
The French Revolution of 1789 and the Napoleonic Wars that followed shook the foundations of European monarchies. The execution of Louis XVI in 1793 demonstrated that not even kings were safe from popular wrath and forced the surviving royal houses to rethink their relationship with their subjects. In Spain, the French invasion of 1808 and the imposition of Joseph Bonaparte as king provoked the War of Independence, a conflict that mixed patriotic resistance against the invader with an incipient liberal revolution that would culminate in the Constitution of Cadiz of 1812.
After the defeat of Napoleon and the restoration of Ferdinand VII in 1814, the Spanish monarchy attempted to return to absolutism, but the liberal ideas had already taken deep roots. The 19th-century Spain would be marked by the tension between absolutists and liberals, with alternating periods of reaction and progress. During this turbulent century, the marriage policy of the Spanish royal family continued to be a matter of state, but the marriages between close relatives that had characterized the Austrias were no longer contemplated. Consanguinity, although not explicitly mentioned in official documents, was a ghost that the Spanish royal house sought to avoid.
However, the memory of Charles II and the degeneration of the Spanish Austrias endured in the collective memory, gradually transforming into a kind of “Black Legend” that exaggerated some aspects and distorted others. The physical deformities of “The Bewitched” were amplified in popular tales, adding fantastic elements, although such characteristics are not historically documented. These exaggerations reflected the impact that the figure of Charles II had had on the popular imagination: a physically deformed and mentally limited king, victim of the marriage policies of his own family, who had presided powerlessly over the final decadence of the once-powerful Spanish Empire.
Modern science has provided new perspectives on the case of Charles II. Genetic studies and retrospective analyses of historical records confirm that extreme consanguinity was probably the main cause of his multiple health problems. Researchers have identified several possible genetic conditions that could explain his clinical picture, including Klinefelter syndrome, acromegaly, combined pituitary hormone deficiency, and distal renal tubular acidosis, among others.
What is clear from a modern scientific perspective is that Charles II presented multiple characteristics consistent with what is known as “inbreeding depression,” a phenomenon well-documented in population genetics. This phenomenon occurs when endogamy increases the probability that deleterious recessive genes express themselves phenotypically, causing various physical and cognitive problems.
The case of Charles II is not unique in history. Other royal dynasties, such as the Ptolemies of ancient Egypt or the Romanovs of Russia, also practiced endogamy with negative consequences. However, few cases are as well-documented or had such profound historical consequences as that of the last Spanish Habsburg.
The extinction of the Spanish branch of the Habsburgs in 1700 marked the end of an era for Spain and for Europe. The empire where the sun never set ceded its hegemonic position to emerging new powers like France and Great Britain. The War of the Spanish Succession redrew the European political map and established a new balance of power that would last until the Napoleonic Wars.
On the dynastic level, the Spanish Bourbons, descendants of Philip V, learned the lesson of their predecessors and avoided extreme consanguineous marriages. Although they continued to marry mainly with members of other European royal houses, they sought to expand their genetic pool through unions with less-related families. This more prudent policy contributed to the survival of the Spanish Bourbon dynasty, which, despite multiple crises and a brief exile during the First Republic (1873–1874), continues today in the person of King Felipe VI, a direct descendant of Philip V.
The saga of Charles II and the Spanish Austrias reminds us that even the most powerful are subject to the laws of biology. The marriage policy that initially seemed to serve short-term dynastic interests and maintain power within the family ended up causing the biological extinction of the dynasty and bringing devastating consequences for the empire they had forged.
This history also reveals to us how societies interpret and reinterpret their past in the light of new knowledge and values. What in the 17th century was seen as a spell or a divine punishment, today is understood as the predictable result of prolonged endogamic practices. The monsters of yesteryear are the genetic victims of today, and the superstitions of yesterday have given way to scientific explanations.
However, despite these advances in our understanding, the figure of Charles II continues to exert a strange fascination. His elongated face, immortalized in the portraits by Carreño de Miranda and Claudio Coello, looks at us from a remote past, reminding us of the fragility of power and the unforeseen consequences of human decisions.
In the halls of the Prado Museum, where the portraits of the Spanish Austrias hang, visitors can follow the progression of the characteristic family prognathism, from its moderate expression in Charles V to its extreme manifestation in Charles II—a visual testimony of how a physical characteristic amplified by generations of endogamy became the symbol of a dynasty and, finally, the presage of its fall.
The history of the Spanish Austrias teaches us that power, however great it may be, cannot indefinitely defy natural laws. Decisions taken for political or dynastic reasons can have biological consequences that, in the long term, undermine the very objectives they intended to secure. In a world where advances in genetics and assisted reproduction pose new possibilities and ethical dilemmas, the lesson of the Austrias remains relevant: genetic diversity is essential for the health of any population, whether a royal family or an entire species.
The “incestuous kiss” of the title, a metaphor for the consanguineous marriages that characterized the dynasty, did not give birth to a baby with a tail—a folkloric exaggeration without historical basis—but it did give birth to generations of individuals with increasingly serious health problems, culminating in Charles II, whose inability to father an heir effectively sealed the fate of the Spanish Empire.
Historical truth, stripped of fantastic elements, proves equally dramatic and cautionary. One of the most powerful dynasties in European history, victim of its own marriage policy, became biologically extinct while the vast empire it had built fragmented and passed into the hands of other powers. It is a story of power and weakness, of greatness and decadence, of political ambition and human fragility—a story that reminds us that, in the final analysis, we are all subject to the same natural laws, regardless of our rank or wealth. And in that reminder resides, perhaps, the most valuable lesson we can extract from the Spanish Austrias.
