Charles II of Spain was impotent and could not father children. It was part of his family legacy of inbreeding. He probably suffered from two genetic disorders. First, there was combined pituitary hormone deficiency, a disorder that made him short, impotent, infertile, weak, and have a host of digestive problems.
As a result Charles' aunt was also his grandmother. At the time of his birth the Habsburgs ruled the Netherlands, Belgium, and parts of Germany as well as Spain. However after 16 generations of inbreeding, Charles II was considered “too deformed and intellectually stunted” to rule properly.
The mandible of Charles II was so badly deformed that he could barely speak or chew, and thus he had to swallow his food almost entirely, which often caused him indigestions and vomiting (Fig. 1) [8]. He is known in history as El Hechizado (the Bewitched).
The Emperor with the highest inbreeding coefficient was Leopold I (F=0.1568) and the second highest was Ferdinand II (F=0.1390), while the Spanish king with the highest inbreeding was Charles II (F=0.2538) and the second highest was Philip III (F=0.2177).
He had the mind of a child and his inability to produce an heir would tip Europe into a decade of war. Yet at the close of the 17th century it often seemed that the most extraordinary thing about Charles II of Spain was his unusually large chin.
Charles Darwin, who was married to his first cousin, Emma Wedgwood, was one of the first experimentalists to demonstrate the adverse effects of inbreeding and to question the consequences of consanguineous mating.
Consanguineous unions range from cousin-cousin to more distant relatedness, and their prevalence varies by culture. Prevalence is highest in Arab countries, followed by India, Japan, Brazil and Israel.
Diana's royal roots
In addition, this royal connection means that Diana and her husband Prince Charles were very distant cousins, via several lines. In particular, they each descend from a daughter of Henry VII: Margaret, who married James IV of Scotland, and Mary, who married Charles Brandon.
In fact, many royals have married relatives over the past hundreds of years since they look to other royalty for a mate. Charles and Camilla are supposedly second cousins, once removed, through their shared ancestor, King Edward VII, it is said.
King John I may forever be known as a Bad King following that seminal history textbook 1066 and All That, but according to history authors, it is Henry VIII who should bear the title of the worst monarch in history.
Louis III died on 5 August 882, aged around 17, at Saint-Denis in the centre of his realm. He was chasing after a girl, who was retreating to her father's house, when he hit his head on the lintel of a low door and later died.
He is Cyrus the Great of Persia, who in the mid-6th century BC ruled the greatest empire the world had ever known. He started as the chief of a downtrodden tribe that overthrew its masters, and he went on to ensure that for the next couple of centuries no other nation would conquer his people again.
In Europe, the practice was most prevalent from the medieval era until the outbreak of World War I, but evidence of intermarriage between royal dynasties in other parts of the world can be found as far back as the Late Bronze Age.
They said that inbreeding so incapacitated the Habsburgs that by the death of King Charles II of Spain in 1700, they were virtually unable to reproduce. From 1516 to 1700, it has been estimated that over 80% of marriages within the Spanish branch of the Habsburg dynasty were consanguineous.
Charles was more inbred than an average child of a brother-sister pairing: his parents, both born to first cousins, were uncle and niece. And Spain fared poorly under his reign. His failure to produce an heir set off a war that cost the country parts of modern Belgium and Italy.
The West Virginian family has a long and complicated history of inbreeding with early reports stating that the three siblings' now-deceased mom and dad were brother and sister. The family later clarified that they were double first cousins — meaning that they share both sets of grandparents.
The Whittaker family, from Odd, West Virginia, are so inbred that many members have clear mental disabilities and cannot properly speak. Danny Ray Whittaker, who goes by Ray, can only communicate via grunts and barks.
“The Habsburg dynasty was one of the most influential in Europe, but became renowned for inbreeding, which was its eventual downfall. We show for the first time that there is a clear positive relationship between inbreeding and appearance of the Habsburg jaw.”
Camilla Is Related to Both Diana and King Charles
Strangely, they are also both related to the late Princess Diana through shared ancestry dating back to King Charles II. Also note that Camilla's great-grandmother was a mistress to King Edward VII, the great-great-grandfather of King Charles.
As Catherine, the Princess of Wales stepped out in a stunning blue and red robe, she bore a striking resemblance to her late mother-in-law Princess Diana.
It comes as little shock to some, as millions of people do indeed have ties to the Royal Family in some way. According to the U.K.'s Channel 4, Patrick explained Kate's familial connection to William as being "fourteenth cousins once removed through his mother and fifteenth cousins through his father."
Of the practicing regions, Middle Eastern and northern Africa territories show the greatest frequencies of consanguinity. Among these populations with high levels of inbreeding, researchers have found several disorders prevalent among inbred offspring.
They created the “50/500” rule, which suggested that a minimum population size of 50 was necessary to combat inbreeding and a minimum of 500 individuals was needed to reduce genetic drift. Management agencies tended to use the 50/500 rule under the assumption that it was applicable to species generally.
While not widely practiced, first-cousin marriage is legal in 19 states, and some first-cousin marriages are legal in six states. Sexual relations and cohabitation are only prohibited in nine states. Approximately 0.2% of all marriages in the United States are between second cousins or closer.