16 Royals Who Suffered From Hereditary Mutations And Defects Caused By Inbreeding

13. Princess Nahienaena’s People Turned Against Her For Incest

Protestant missionaries educated princess Nahienaena of Hawaii in the early 1800s. She was also romantically involved with her brother, King Kamehameha III, since childhood and was all too eager to marry him, much to the chagrin of the missionaries. Tradition ran against the power of the ministers, as the royal family was accustomed to intermarriage to keep the bloodline pure. When the siblings were married in 1825, she was expelled from the church.

Nahienaena was sincerely repentant, as she greatly respected the missionaries. However, her repentance was not accepted by the church, and she was soon found to be pregnant with her brother’s child. With her people now converted, they shunned her, and she lived in isolation until the child’s birth. The baby died within just a few hours, probably because of genetic problems stemming from generations of inbreeding, and the disgraced princess lived the rest of her life in shock and grief. She was finally accepted back into the church shortly before her death.

Age: 21 (1815-1836)
Born: Keauhou, Hawaii

14. King Rama V Had Many Wives But Only Showed One In Public

King Chulalongkorn, also known as Rama V, was immortalized in the fictionalized story of Anna and the King, as he was one of the children educated by the British educator, Anna Leonowens. The Chakri dynasty, of which Rama V was a member, routinely engaged in marriages among cousins and other relatives. Kings usually had harems, leading to dozens of children. Many of the half-siblings that grew up in these harems married each other.

Unlike many royals who suffered from the worse aspects of inbreeding, like the Habsburg jaw and insanity, King Rama V is credited with the modernization of Siam, now known as Thailand, and for keeping it from becoming colonized by the British. He built public hospitals and a railway and also abolished slavery. With his harem of 153 wives, concubines, and consorts, he fathered 77 children. Many of them were sent to Europe for formal education.

However, because of the disgrace which he knew would be looked upon him by Western leaders, he only showed one of his wives — Queen Saovabha — in public. The shame, he knew, would be due not so much to the polygamy but rather to the incest, as many of his wives were biologically related to him. However, he claimed that his preference for being shown with only one wife was due to custom.

15. Nero’s Insanity May Have Been From Inbreeding

Much modern scholarship has focused on trying to understand the darker underbelly of Roman culture, such as why there was so much lead poisoning and how it contributed to the fall of the greatest empire in history. One particular aspect of Roman history that is interesting to some historians is how incest and inbreeding may have generated insanity among the emperors. Moreover, perhaps no emperor is more famous for madness than Nero, the man who fiddled while Rome burned and was accused of having sex with his own mother.

The Roman royals often intermarried for the same reasons as later European royal families: to keep wealth and prestige within the family and reduce contention over who should be heir to the throne. Nero was the son of a niece and her uncle, Agrippina and Claudius, who may have had an inbred pedigree going back generations. Agrippina agreed to marry him to strengthen her son’s claim to the throne, something that ultimately proved to be a somewhat dangerous thing for the citizens of Rome. Not only had lead poisoning severely depleted his mental faculties, but his inbreeding may have assumed that he didn’t have many faculties to begin with.

Age: 31 (37AD-68AD)
Born: Antium, Italy

16. Caligula’s Bloodthirst Was Likely Fueled By Inbreeding

Nero may be the most infamous of all Roman emperors, but he was not the only one to have a family tree that grew straight up. Caligula (also known as Gaius Caesar), who has been accused by many of engaging in incestuous relations with his sisters (something that he may or may not have done), descended from a pedigree of biological relatives marrying each other to keep money, power, and the bloodline intact. His reign was defined by both lust and lunacy.

His father, Germanicus, was beloved by the Roman people, and, believing Caligula would possess the same characteristics, they were more than happy to coronate him as the new emperor. However, after an illness six months into his reign, he proved that he was not the same person as his father. Caligula forced parents to watch the tortures and executions of their children. Claiming to be a god, he had a bridge built between the Temple of Zeus and his own palace so that he could more easily convene with the deity. He was assassinated by his unhappy public when, after a sports event, guardsmen stabbed him 30 times.

Where did we find this stuff? Here are our sources:

“Family Tree of the Habsburg Dynasty,” by Dr. Ursula Stickler. The Open University. January 10, 2017.

“Inbreeding and the downfall of the Spanish Habsburgs,” by Razib Khan. Discover Magazine, April 14, 2009.

“Case Closed: Famous Royals Suffered from Hemophilia.” Science Mag. October 8, 2009.

“Five Myths and Truths About Rasputin,” by Albinko Hasic. Time Magazine. December 29, 2016.”

“King Tut Mysteries Solved: Was Disabled, Malarial, and Inbred,” by Ker Than. National Geographic News, February 17, 2010.

“What was the truth about the madness of George III?” BBC Magazine. April 15, 2013.

“10 Mad Royals in History” by Shanna Freeman. How Stuff Works.

“The Tragic Austrian Empress Who Was Murdered by Anarchists,” by Hadley Meares. History. January 4, 2018.

“The Tragic Story of the Mad Queen of Castile Who Slept Next to Her Husband’s Corpse,” by Paolo Chua. Esquire Magazine. April 28, 2018.

“King Ludwig II of Bavaria” The German Way.

“How The Royal Disease Destroyed The Life Of Russia’s Last Tsarevich”. Oleg Yegorov. Russia Beyond. AUG 2018.

“Ferdiand I, Emperor of Austria.” Encyclopedia Britannica. June 25, 2018.

“Cleopatra.” New World Encyclopedia.

“Nahienaena,” Encyclopedia Britannica. November 15, 2007.

“Chulalongkorn, King of Siam.” Encyclopedia Britannica. July 20, 1998.

“Ten Royal Families Riddled With Incest,” by Kindree Cushing. November 26, 2014.

“Caligula Biography.” The biography.com website. April 27, 2017.