Royals Who Suffered From Hereditary Mutations And Defects Caused By Inbreeding

Peter Dugre
Updated September 23, 2021 12.3M views

Long before the concept of "designer babies" created in a lab became the stuff of science fiction, inbreeding in royal families was viewed as a way to ensure genetic purity. Intermarriage ensured that no "common" blood sullied pure, aristocratic bloodlines. Inbred royalty - what could go wrong?

A lot, actually. Birth defects caused by inbreeding were rampant in royal families from Russia to Portugal and even in ancient Egypt, where the practice of sibling marriage was considered godly behavior. Royal family hereditary diseases and deformities caused by inbreeding - such as porphyria, among others - get handed down through thin gene pools, particularly in the many cases where intentional close marriage is used to ensure that royal blood (and its recurrent flaws) are kept in the family. For example, Queen Victoria, a major proponent of pure bloodlines, married her cousin Albert, and the two had nine children who then passed hemophilia to royal families throughout Europe. 

While all these families hoped close intermarriage would keep their royal families stronger, in many cases, illness, madness, infertility and deformities caused by inbreeding ended up tearing them apart.

  • Charles II Had A Massive, Drool-Secreting Tongue

    The product of a long line of Habsburg inbreeding, Charles II (nicknamed "The Bewitched") looked the part. He had what was called the Habsburg Jaw or Habsburg Lip, characterized by a huge tongue, an under-bite, a jutting lower jaw, and a thick lower lip. Technically, the deformity is known as mandibular prognathism. His tongue made it difficult to chew and caused excessive drooling.

    The king was also severely developmentally delayed. He was breastfed until he was 5 and never received any formal education. He was also impotent, so his inability to procreate ended the Habsburg’s hold on the Spanish crown when the king passed in 1700.

    The Habsburg dynasty had been intermarrying for so long that one of Charles's ancestors, Joanna of Castille, appears in his family tree 14 different times. In fact, Charles I was more inbred than he would have been if his parents had been brother and sister.

  • Tsarevich Alexei Nikolaevich's Royal Disease Ended An Empire
    Photo: St. Petersburg Nevsky 24 / Wikimedia Commons / Public Domain

    Tsarevich Alexei Nikolaevich's hemophilia contributed to the fall of the Russian imperial dynasty in 1917. While no one in the ruling Russian House of Romanov was known to carry hemophilia (a potentially fatal genetic disease where blood does not clot normally), Alexei's father Tsar Nicholas had married into the family of Queen Victoria of England, who was part of a clan of passionate inbreds. Tsarist Alexandra was Victoria's granddaughter. 

    Desperate to save her son's life, Alexandra sought mystical intervention in the form of Rasputin, the "Mad Monk.” Inviting a lascivious man like Rasputin, known for his tastes for alcohol and lovers of all genders, didn’t go over well with the aristocracy. The Russian rulers, however, were convinced that Rasputin’s treatments were effective in saving their son.

    The mystic Rasputin gained greater influence at court, wielding increasing power over the lives of the royals and surreptitiously governing Russia. The disorder in the royal house and the questionable company the rulers kept helped spur the Russian Revolution of 1917, and as a result, the entire royal family was executed. 

  • King Tut Suffered A Deformed Skull Due To Sibling Marriage
    Photo: Jon Bodsworth / Wikimedia Commons / Public Domain

    King Tut Suffered A Deformed Skull Due To Sibling Marriage

    Although his legacy is as the golden boy pharaoh of ancient Egypt, DNA tests of King Tut's mummified corpse show that this ruler of Egypt circa 1300 BCE was actually a feeble-bodied genetic misfit, owing to the Egyptian royal tradition of brothers and sisters marrying one another. King Tutankhamun took the throne at age 9 and survived only until the age of 19. He likely had a cleft palate, a club foot, and scoliosis, as well as an elongated, deformed skull.

    Egyptian pharaohs revered sibling marriage, influenced by the legend that the god Osiris married his sister, Isis, to maintain a pure bloodline. There were even instances of "double niece" marriages (defined as when a man marries a girl who was the offspring of his brother and sister).

  • A Hereditary Blue Urine Disease May Have Driven King George III Insane
    Photo: Allan Ramsay / Wikimedia Commons / Public Domain

    A Hereditary Blue Urine Disease May Have Driven King George III Insane

    King George III of England, whose reign was famously marked by losing the American Revolution, likely had a genetic disorder that affected his mind more noticeably than his body. He is believed to have suffered from porphyria, a disease that makes a patient’s urine bluish-purple and causes bouts of insanity (though arsenic poisoning and bipolar disorder have also been suggested as possible causes).

    George III routinely checked out from his royal duties to escape to seclusion and private recovery at Kew Palace. He was prone to babbling delusions in his later life and subjected to extreme treatments including straight jackets, leeching, and ice baths to calm him. Modern medical testing shows porphyria was common in the highly inbred House of Hanover, to which King George III belonged.

    George III spent the final decade of his reign in hiding and eventually lost his vision and hearing.

  • The Mad Queen Maria I Of Portugal Suffered Royal Temper Tantrums
    Photo: Biblioteca Nacional de Portugal / Wikimedia Commons / Public Domain

    The mentally unstable Queen Maria I was married to her uncle. Known as the Mad Queen, she was given to delusional fits and religious obsessions. Maria spent much time in seclusion, but her howling could be heard throughout the royal estate.

    Her grip on sanity was so feeble that by 1799, her son John was the unofficial ruler while she remained queen in title only. Eventually, the family fled to Brazil during the Napoleonic Wars, and Maria I passed in a convent.

  • Joanna Of Castile's Inherited Madness Was Exacerbated By Her Husband's Passing
    Photo: Web Gallery of Art / Wikimedia Commons / Public Domain

    Joanna of Castile was the older sister of Catherine of Castile, the poorly treated first wife of Henry VIII. Joanna wasn't originally intended to inherit the thrones of Castile and Aragon (the kingdoms that would be combined to create the nexus of the Spanish Empire), but when she outlived a number of siblings, she ended up wearing the crown. This wouldn't have been a big issue had she been a competent and capable ruler, as her mother had set an unusual precedent for strong Spanish queens, but her mental state was slightly impaired, to say the least.

    When she married her Habsburg husband, remembered to history as Philip the Handsome, she fell desperately and completely in love with him. Unfortunately, their love story wasn't a happy one and he cheated on her multiple times before passing at an early age, leaving her a bereaved widow. Well, she was a little more than bereaved and supposedly lost her sanity to such a degree that she was removed from power and spent the rest of her days crying over her husband's remains. Yes, she held onto it.

    Her ancestors, members of the extinct royal House of Trastámara, had been marrying members of their own family for generations, and it's incredibly likely this trend was a leading cause of Joanna's mental instability.

  • King Ludwig II Of Bavaria's Family Had Been Going Mad For Ages - And He Paid The Ultimate Price For It
    Photo: Michael Petzet / Wikimedia Commons / Public Domain

    Like his cousin, the Empress of Austria, King Ludwig II of Bavaria was a member of the old Wittelsbach dynasty. The family had been intermarrying for generations, and the effects of such close consanguinity were leaving their marks upon the family members. Ludwig was known for being absolutely out of touch with reality and preferred to live in a self-made fantasy, which would have been fine had he not been a king with a job to do. While he went about building castles and sailing in swan-shaped boats, the Bavarian government was tearing their hair out over the inadequacies and wastefulness of their king.

    Ludwig was eventually deposed, but not happily - the day after he was removed from the throne, his body was found by a lake, clearly the victim of foul play.

  • Queen Victoria May Have Spread Hemophilia Throughout European Royalty
    Photo: Alexander Bassano / Wikimedia Commons / Public domain

    Queen Victoria, known as the matriarch of European royalty, had hemophilia, a blood-clotting disorder. Though she managed to avoid most serious side effects of the disease throughout her lengthy lifetime, the ancestors who brought it with them to royal houses throughout Europe were not so fortunate. Typically, hemophilia is acquired by women through both parents' genes and would have had nothing to do with the fact that Queen Victoria was married to her first cousin, Prince Albert.

    However, historians have disputed whether or not the queen's father - Edward, the Duke of Kent - was, in fact, her biological one. 

  • Ferdinand I Of Austria Had A Host Of Mental And Physical Problems, Yet Reigned For 13 Years
    Photo: Jeanlous / Wikimedia Commons / CC-BY-SA 4.0

    Ferdinand I Of Austria Had A Host Of Mental And Physical Problems, Yet Reigned For 13 Years

    Emperor Franz II of Austria married his double first cousin Marie-Therese, but their son paid the price for the proximity of their blood. Ferdinand I was born in 1793 with a hydrocephalic head containing fluid build-up and pressure that severely challenged his intelligence and motor skills. He also had the Habsburg jaw and a tongue far too large for his overbite, a body too small for his head, and epilepsy.

    Still, he ruled from 1835 to 1848.

  • While Cleopatra is known in popular culture for her slender figure and stunning beauty, it's more likely she wasn't that at all. Specifically, archeologists believe Cleopatra suffered from excessive weight, and her family was to blame.

    In the Ptolemy tradition, Cleopatra's family regularly practiced incest. Obesity in her family was exacerbated by the incest. On top of that, many believe she and her brother and sister were both afflicted with less-than-attractive features.

  • Princess Nahienaena Lost Her Baby Because Of Incest
    Photo: Robert Dampier / Wikipedia / Public Domain

    Princess Nahienaena Lost Her Baby Because Of Incest

    Princess Nahienaena of Hawaii became romantically involved with her brother - King Kamehameha III since the two were children. But when she sought to marry him, Christian missionaries vocally opposed the union. They were never married, but did conceive a child. Unfortunately, because of complications many believe were do to incest, the baby only lived for a few hours. 

    Nahienaena never got over the child's passing and died shortly thereafter in 1836.