Our search for inbreeding depression continues in the royal houses of Europe...
People often say that European royals are more inbred than the general population given the many intermarriages between the royal houses which took place over the generations. It is because of this that, for example, all the crowned heads of Europe can trace their ancestry back to William the Conqueror (1027-1087). And if you look at the family trees of Queen Elizabeth and her husband Prince Philip, you will see that they are not-so-distant cousins: King Christian IX of Denmark (1818-1906) was both Elizabeth's great great grandfather and Philip's great grandfather while Queen Victoria (1819-1901) was great great grandmother to both of them.
Here's a few more interesting facts about the royal gene pool:
(1) The most recent common ancestor of all the current crowned heads of Europe is John William Friso, Prince of Orange (1687-1711).
(2) Queen Sofia, the wife of King Juan Carlos of Spain, is Philip's first cousin once removed as King George of the Hellenes (1845-1913) was Philip's grandfather and Sofia's great grandfather.
(3) You may have heard the story of Anna Anderson who claimed to be Anastasia, the daughter of the last Russian tsar who was killed by the Bolsheviks in 1918 (there's a good movie loosely based on her story starring Ingrid Bergman and Yul Brenner). In 1994, ten years after her death, a test was done comparing Anderson's DNA to that of Prince Philip with the results proving that she could not have been who she claimed. This is because the real Anastasia would have been related to Philip (and Elizabeth) through Christian IX and Queen Victoria who were her great grandparents.
(4) Anastasia's father, Nikolai II (1868-1918), and King George V of England (1865-1936, the Queen's grandfather) were like "identical cousins." Their mothers were both daughters of Christian IX.
I should note that a lot of new stock has been introduced into the royal gene pool in recent generations as many royals are now outbred to non-royals (cf. Prince Charles and Andrew's marriages to Diana Spencer and Sarah Ferguson – Englishwomen from aristocratic families who were only distantly related to their husbands – and King Harald V of Norway's marriage to Queen Sonja who is a commoner).
Stay tuned for the most inbred royal of them all.
Images: Photograph of King George V of England and Tsar Nikolai II of Russia taken in Berlin, 1913 is in the public domain.