Bella Rossa shared this in the comments. (By the way, thanks, Bella. And welcome to Melinda June!) I'd known Charles II of Spain was a suspected inbred, but had never really looked at the chart. Oh my. Circles are very very bad.
Charles II is known in Spanish history as El Hechizado ("The Bewitched") from the popular belief — to which Charles himself subscribed — that his physical and mental disabilities were caused by "sorcery" rather than the much more likely cause: centuries of inbreeding within the Habsburg dynasty (in which first cousin and uncle/niece matches were commonly used to preserve a prosperous family's hold on its multifarious territories)...His great-great-great grandmother, Joanna I, (Joanna the Mad), mother of the Spanish King Charles I who was also Holy Roman Emperor Charles V — became completely insane early in life; the fear of a taint of insanity ran through the Habsburgs. Charles descended from Joanna a total of 14 times — twice as a great-great-great grandson, and 12 times further...
Charles II was the last of the Spanish Habsburg dynasty, physically disabled, mentally retarded and disfigured (possibly through affliction with mandibular prognathism — he was unable to chew). His tongue was so large that his speech could barely be understood, and he frequently drooled. He may also have suffered from the bone disease acromegaly. He was treated as virtually an infant in arms until he was ten years old. Fearing the frail child would be overtaxed, he was left entirely uneducated, and his indolence was indulged to such an extent that he was not even expected to be clean. When his half-brother John of Austria the Younger, a natural son of Philip IV, obtained power by exiling the queen mother from court, he insisted that at least the king's hair should be combed.
The only vigorous activity shown by Charles was shooting, which he occasionally indulged in the preserves of the Escorial.But I hear he was a Harvard MBA.