Researchers found that the last of the Spanish line, Spanish king Charles II, was the offspring of a marriage that was almost as genetically inbred as an incestuous relationship between a brother and sister or parent and child. It is likely the reason he was infertile.
"Charles II of Spain was nicknamed El Hechizado – The Hexed – because people at the time thought that his physical and mental disabilities were the result of sorcery," writes Steve Connor. "Now a study into the genetics of his immediate ancestors has found that he was so inbred that he probably suffered from at least two inherited disorders.
"Despite his deformities and severe health problems, Charles had married twice in the hope of continuing the rule of the Hapsburgs, but he was incapable of fathering an heir and died childless at the age of 39. He was the last of a long line of Hapsburgs and it spelled the end for the Spanish branch of the dynasty."
In fact, it is a bit unfair to compare the Hapsburgs to dog-breeding as of course there was no attempt at all by the family to select for rude good health - the over-riding criteria was just does your name start with "Haps" and end in "burg" and "ah - you have a severely undershot jaw, too! Great!" (What is known colloquially as the Hapsburg Jaw or Lip - so severe in Charles II that he couldn't chew.) But even if they had made a point of only marrying the healthiest, least-deformed members of the family, in all likelihood the inbreeding would still have caught up with them sooner or later.
As it has now done with dogs.
Read the rest of the excellent Independent article here.
Here endeth today's warning from history.