

Photo Courtesy: [Carlo Raso/Flickr]
Things are about to get ugly
European royal families in the 13th century began to employ an innovative practice in an attempt to both consolidate and spread their power and influence. They began to marry their cousins. Of course, cousins weren’t the only thing on the marriage-menu, and they also often intermarried between families. However, these families typically shared a common ancestor, meaning that they were still related.
In theory, this practice would ensure a stronger, more connected European royalty, helping to quash fighting, warring, and general discontent among those families. And, for a while, it worked. But centuries of inbreeding ended up dooming future generations. Rare, recessive genes that were previously unexpressed became dominant, resulting in a wide range of diseases and disorders.
Hemophilia, often called ‘the royal disease,’ was passed on by Queen Victoria to a smattering of European descendants, including Alexei Romanov, the last Tsarevich of Russia. This unfortunate, but seemingly insignificant affliction would change the course of Russian history – and world history – forever.
But the Romanovs were not the only royal family to suffer from a legacy of inbreeding. The House of Habsburg was particularly cursed, with descendants exhibiting the notorious Habsburg chin in addition to other deformities.
The House of Habsburg
The Habsburgs trace their origins to the Habsburg Castle in modern-day Switzerland. But their real rise to power begins in 1273 when Rudolf of Habsburg was elected King of the Romans and the Kingdom of Germany.


Until the 18th century, this method worked quite well. But the Habsburg dynasty crumbled like stale bread when Charles II of the Spanish Empire – the last true monarch of the line – was born.
While there had been indicators that the Habsburg line was beginning to deteriorate biologically, not every child born to these familial relations exhibited visible disfigurements. Consequently, the Habsburgs may have believed that their problems did not lie with their marriage practices, but rather with God’s displeasure in their actions.
The Short Life of Charles II
Charles II was the product of a union between an uncle and a niece, making him his parent’s great-nephew and first cousin. His survival was considered to be a horrible miracle, as he suffered from a litany of disabilities and disfigurements.
He was afflicted with mandibular prognathism, making his lower jaw jut out unnaturally. Due to the extreme nature of his condition, speaking and eating were difficult tasks. In addition to inheriting the Habsburg jaw, the young royal also inherited the Habsburg lip and the Habsburg nose.
His physical disfigurements were far more than skin-deep. Author Pedro Gargantilla purports that the physician who performed the autopsy of Charles II discovered that:
“[His body] did not contain a single drop of blood; his heart was the size of a peppercorn; his lungs corroded; his intestines rotten and gangrenous; he had a single testicle, black as coal, and his head was full of water.”
He died at the age of 38, having produced no heirs. It has been theorized that in addition to his mental incapabilities and physical weaknesses, Charles II may have been a hermaphrodite. For centuries since his birth and death, historians and physicians have debated the impact that inbreeding may have had on his condition.
Modern science has proved that the Habsburg chin is related to inbreeding, though why it manifests itself in some offspring – but not all – continues to remain a mystery. It’s important to note that while Charles II suffered from illness all of his life, his two sisters did not.
Descendants of the original Habsburg line are alive today, though they no longer adhere to their ancient custom of marrying within the family. As such, the Habsburg chin remains a fascination of the past and a reminder of the harm that inbreeding can do.
A deeper dive — Related reading from the 101:
- June 28, 1519: Charles I scored the exhausting role of Holy Roman Emperor | History 101
Charles I got more than he bargained for (literally) when he became Holy Roman Emperor - Human sexes use their whole genomes distinctively | Science 101
Gender may determine the likelihood of catching or inheriting specific diseases and afflictions