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Home » Inbreeding Among Royals: 14 Monarchs Who Experienced the Side Effects of Incest

Inbreeding Among Royals: 14 Monarchs Who Experienced the Side Effects of Incest

It may seem taboo today, but before, monarchs will do anything — and we mean, anything — to preserve their power and one of the ways they did this was to marry within the family. The act is called consanguinity where biological relatives marry each other is a foolproof plan to destruction. Inbreeding can lead to diseases and deformities throughout history, monarchs who are produced in inbreeding often led their rule in mayhem and disarray. Let us review the list of royals who had their constituents suffer due to the genetics effects of inbreeding.


Coming from the royal line of Habsburgs the most powerful family in Europe for hundreds of years, King Charles had in him the trademark characteristic of a Habsburg: oversized jawline and a large tongue. This made it difficult for King Charles II to speak and eat and is known to drool a lot. It is said that he is severely inbred that he is unable to walk until he is eight years old but even then he walks with a lot of difficulties.

King Charles II married twice but was not successful in producing an offspring, possibly an effect of him being a product of inbreeding. Because he wasn’t able to produce an heir, he was the last Habsburg to rule Spain.


Born and ruled years before Charles II, Joana of Castile was the daughter of King Ferdinand and Queen Isabella who are second cousins (and the older sister of another famous monarch Catherine of Aragon who also had trouble in rearing a child largely due to being a product of inbreeding).

Joana is known for being an intelligent, inquisitive, but moody child. When she was 16, she tied the knot with the son of the Holy Roman Emperor Maximillian I — Philip the Handsome — through an arranged marriage. Philip is known to be such a huge womanizer but it seems Joana is so smitten she can easily look past his adultery.

Her first mental breakdown happened when she ascended to the throne because of the death of her older siblings and it was made worse by the behavior of her husband towards her (philandering and constant political insecurity). She first showed hostility when she found one of her husband’s mistress which she immediately stabbed in the face. Joana remained smitten and madly in love with her husband that when he died of typhoid fever at the young age of 28 (she believes that her husband was assassinated through poison), she refused to depart from his corpse. Joana slept beside her husband’s dead body every night.


The famous Queen of England like to match her children with royalty from other European countries and as a result, Europe in the 19th and 20th centuries was pretty much a family business. For instance, her daughter Alice was married off to a Russian tsar and gave birth to Alexandra Romanov, the last Tsarina of Russia. It was also known that her lover Prince Albert was her first cousin and their children are, obviously, products of inbreeding. The most evident effect of inbreeding in this royal brood is hemophilia or the disorder which prevents blood from clotting. Queen Victoria was able to pass this trait to her children and grandchildren and while she, herself, did not have any form of suffering in possessing this disorder, her children and grandchildren did: one of her children and five of her grandchildren died brought on by complication of hemophilia.

Both the queen and Prince Albert possess the recessive gene that caused hemophilia but Queen Victoria’s type of hemophilia is rather unique and this raised speculations that Edward, Duke of Kent is her biological father. Further evidence fueled this speculation as researchers explained that for the children to have hemophilia, both of the parents should possess the recessive gene and it is quite curious for a type of hemophilia as rare as Queen Victoria’s to be passed down on her offsprings.


Another Habsburg on the list, Ferdinand I is a direct descendant of Joana the Mad and born to Emperor Franz II and Marie-Therese who are double first cousins. Ferdinand I has hydrocephaly (big head shape brought by the presence of water in the brain), a common sight among those who belong to the royal line of Habsburg.

Like his predecessors, Ferdinand I possess the “Habsburg jaw” and epilepsy. Although physically weak, he was able to reign as king. In his lifetime, he was able to rule the unified kingdoms of Hungary, Austria, Bohemia, Lombardy, and Venetia. However, because of his predicaments, the affairs of the kingdom were controlled by his counselors and regents. One of Ferdinand I’s quirks was to sit down on the open end of a wastebasket and roll around on the floor. Interestingly enough, he was able to rule the kingdom for 18 years and lived until the age of 82.


The Romanovs are famous for being a long line of leaders in Russia but it only took one Romanov to topple a kingdom because of a series of wrong decisions that led to their downfall at the hands of the Socialist Republic. The last Romanov family became some sort of a household tale. Alexei Romanov is a grandson of Queen Victoria and he inherited his grandmother’s hemophilia. His frequent bleeding often threatened his life that his mother employed the help of Rasputin.

Despite the ruling class’ disapproval of Rasputin and his alcoholism and sexual promiscuity, the Tsar and his wife believed he can heal Alexei.


Another royalty from the line of Queen Victoria, Princess Victoria is lucky that the only thing she shares with her grandmother is her name and not the rare disorder that prevents blood from clotting called hemophilia. However, Princess Victoria still suffers from the effects of inbreeding as her grandmother insists she marries her cousin, the Grand Duke of Hesse. The two frequently fight because of the Duke’s infidelity and was caught red-handed by Princess Victoria more than a couple of times. It was said that Princess Victoria was volatile during their arguments. The couple was divorced after the death of Queen Victoria and their eight-year-old daughter Elisabeth of Hesse.


George III is known for being the ruler when England lost their biggest colony — America. He belonged to the same family which Queen Victoria belongs to and is a product of inbreeding as well. Experts first hypothesized that George III suffered from porphyria, a condition that causes bouts of madness and turns urine purplish-blue.

Recent analyses, however, argued that George III does not have porphyria but is instead suffering from mental illness — more specifically, bipolar disorder — which is most probably caused by his inbreeding. The researchers pointed out that in George III’s manic episodes, his writing was remarkably different and was known to talk non-stop until foam comes out of his mouth. He is known to history as the Mad King and his physicians would treat him using a straitjacket and ice baths. His manic episodes could have been the reason why he lost control of the American colony when the revolution happened.

Aside from his mental illness, George III was known to suffer from skin conditions that were treated with medicine made from Gentian. This medicine was probably the reason why his urine turned blue.


Queen Maria may be known as Maria the Pious and this obsessively devout behavior is a window to the mental illness brought on by genetic disorders as a result of being an interbred offspring. As a matter of fact, Maria was known to be so devout that when her confessor died, she would have bouts of raging temper tantrums and scream about her “damnation”. Her screams are not exactly a pleasant sound since she is known to howl and create animalistic noises while shrieking.

Maria and England’s resident mad king Geroge III share the same physician — Dr. Francis Willis. He diagnosed Maria the Pious as insane and the poor queen underwent horrible treatments like ice baths, induced blistering, and taking laxatives. Looking at it from a modern medical perspective, it is not surprising that none of those worked and the queen was rendered unfit to attend royal duties.

However dire the effects of inbreeding in Maria, it did not stop the practice. She married her uncle and their son also suffered from genetic challenges brought forth by this union.


At first look, Empress Elisabeth is a sight to behold — she is widely known for her beauty. However, beneath all her beauty lies her mental illness most probably because she is a product of a long practice of inbreeding in the House of Wittelsbach. Empress Elisabeth suffers from depression and anorexia: she has been known to be withdrawn and melancholic and because she is always nervous, she rarely touches her food. What’s worse is that although she eats small amounts of food, she obsessively does exercise for several hours a day.


Empress Elisabeth’s cousin also suffered mental illness from genetic disorders resulting from inbreeding. People are familiar with King Ludwig as the king who was completely out of touch with reality. King Ludwig descended from the Habsburgs who are notorious for their inbreeding practice. He is known for building grand palaces for escaping reality. Back when he was a child, this mother noticed his interest in dressing up and displays a vivid imagination. By the time he rose to power at the age of 18, he was still fond of the dream world he had created. To keep himself within that world, he became the patron of composer Richard Wagner and supported artistic expression.

However, the country is struggling with the expenses and their ruler, although physically present, prefers the comfort of grand palaces and not its responsibilities.


As long as the feudal system persists, so is consanguinity. The behavior was already observed even before these European monarchs even existed, back to the time of King Tutankhamen. Ancient Egyptian rulers followed the tradition of marrying within the family to keep the bloodline pure. One of ancient Egypt’s famous pharaohs is a product of inbreeding and it showed in his physical appearance. Recent studies suggest that King Tut is frail, sickly, and possesses a cleft palate, a club foot, an elongated skull, and a very persistent case of malaria.

DNA scans of King Tut’s mummy reveal that he is a product of “high-level incest” and Nefertiti may not be his mother after all. Researchers hypothesized that King Tut’s mother is probably King Akhenaten’s sister. This changed King Tut’s history drastically as it was previously assumed that he was murdered. Instead, researchers are convinced that due to his compromised immune system brought on by inbreeding, the young pharaoh died from malaria and the inability to heal the necrosis in his foot.


Pop culture painted Cleopatra as a sexy seductress who was able to lure Roman men. However, there are theories that explain that she may not exactly be pop culture’s icon for an ancient femme fatale. Researchers say that Cleopatra may actually be obese and this is due to being an inbred offspring during the Ptolemaic era of Egypt. During that time, kings are required to marry their sisters to acquire power. For instance, when Cleopatra rose to power, she married her 10-year-old brother and married her other brother.

Scans of the Egyptian queen’s remains show that she may have a hooked nose, a round face, and fat hanging under her chin and all that talk of her being some kind of personified Venus is just Roman propaganda.


When Protestant missionaries colonized Hawaii, they educated people from the ruling class including Princess Nahienaena. However, she was involved romantically with her brother King Kamehameha III much to the horror of the missionaries. Despite their objections, tradition weighed more than the lessons of the Protestants and in retaliation, the Protestants expelled the princess from their church.


Probably the most famous product of inbreeding throughout history, Nero became somehow synonymous with madness. There are a lot of tales regarding Nero’s insanity from how he burned Rome to having sex with his own mother, but one thing is for certain, Nero is an offspring of two related Roman aristocrats — Claudius and his niece Agrippina. Research also shows that widespread lead poisoning could have contributed to Nero’s degrading mental health but because of inbreeding, researchers suggest that he didn’t have many faculties, to begin with.