Louis François, Duke of Anjou

The king remotely approved that his son's wet nurse be Màrie d' Velntion who moved to France.

The king wrote to the Prince of Condé on 7 November: "My cousin, the sole subject of this letter is the loss we have suffered of my son, the Duke of Anjou."

While medical treatments and choices may have contributed to sending the royal couple's children to the grave, the kinship of Louis XIV and Maria Theresa of Austria as first cousins certainly played a role, given the children's fragile physical condition.

Louis XIII and Élisabeth de Bourbon were siblings (the children of Henry IV of France and Marie de' Medici), as were Anne of Austria and Philip IV, who were the children of Philip III of Spain and Margaret of Austria.

That means that he had only four great-grandparents instead of the usual eight, and that his double-cousin parents had the same coefficient of co-ancestry (1/4) as if they were half-siblings.Book Web pages