GenealogyInTime Magazine 1 Reply This is the official family tree of Charles II of Spain. Notice how unlike a normal family tree, it loops back on itself. Several people are related to each other in more than one way, which is not natural.
Inbreeding of Spanish Royalty
The Hapsburgs ruled Spain for 184 years until the death of King Charles II in 1700. Charles II was a physically and mentally impaired individual who was the product of generations of inbreeding. He was unable to produce offspring and thus effectively ended the dynasty.
All humans carry deleterious genes that under normal circumstances are recessive. These problem genes do not normally become dominant if unrelated people marry and have children. However, repeated consanguineous (related by blood) marriages within an extended family can concentrate deleterious genes with disastrous results. For a powerful royal family such as the Spanish Hapsburgs, inbreeding can impact not just the family, but history itself.
In the case of the Spanish Hapsburgs, they literally bred themselves out of existence. This is ironic given the reason the family married within their own ranks in the first place was to maintain power and control within the family. What the inbreeding eventually accomplished was to finally hand Spanish power over to the French Bourbons.
The amount of inbreeding within a family is measured by what is known as the inbreeding coefficient. This coefficient essentially sums up the various distinct genealogical paths to a common ancestor. The higher the inbreeding coefficient, the greater the risk of abnormal offspring.
Gonzalo Alvarez led a team from the University of Santiago de Compostela in Spain performed a formal genealogy study on the family tree of Charles II (see above). The study is entitled The Role of Inbreeding in the Extinction of a European Royal Dynasty. As is evident from the family tree, Charles II’s genealogy loops back on itself multiple times. Reporting in the journal PLoS, Alvarez’s team found two noteworthy items:
• Charles II’s inbreeding coefficient was so high that it was greater than the offspring from a brother-sister mating.
• The infant mortality rate of the Spanish Hapsburgs was considerably greater than that of the general population. More than ¾ of all Hapsburg children died before the age of ten, in spite of having access to the finest medical resources of the times. The high amount of inbreeding resulted in a high mortality rate.
Above is an official portrait of Charles II. It clearly shows the challenge court painters faced portraying the Hapsburgs. Evident in this sympathetic painting of Charles II is what is known as the “Hapsburg Lip”, a severely elongated lower jaw and drooped lip that was a common recessive trait of all Hapsburgs across Europe. In Charles II’s case, his head was so misshapen that he was unable to chew at all because his top and bottom teeth did not meet.
The genealogy study of the Spanish Hapsburgs shows the dangers of consanguineous unions. However, beyond genealogy, it also had a significant impact on history. Charles II was unable to produce offspring and his death triggered the War of the Spanish Succession (1702-1713). This resulted in several claimants to the Spanish throne, as shown in the family tree below. This family tree also shows how closely the royal families of Europe were related to each other.