1907: The discovery that Leopold, the eighth of Queen Victoria’s nine children, suffered from the hereditary genetic disorder haemophilia, meant that the queen’s daughters might also carry the defective gene. Even if they displayed no signs of the disorder, they could transmit it to their children.
In 1906, Victoria Eugenie, the daughter of Queen Victoria’s youngest child, Beatrice, married the Spanish king, Alfonso XIII. A year later, the queen gave birth to a healthy-looking boy, who, like his father, was named Alfonso. Three weeks after the birth, baby Alfonso was circumcised. Given the risk of haemophilia, the operation was perhaps unwise, but Spanish royal tradition trumped health concerns. The baby’s blood failed to clot and pressure had to be applied to halt the bleeding. After that, a definitive medical diagnosis was hardly necessary – the young prince was clearly a haemophiliac.
Source: Haemophilia, March 2003