Queen Victoria's son, Prince Leopold, died from haemophilia, but no member of the royal family before his generation had suffered from the condition. Medically, there are only two possibilities: either one of Victoria's parents had a 1 in 50,000 random mutation, or Victoria was the illegitimate child of a haemophiliac man. However the haemophilia gene arose, it had a profound effect on history. Two of Victoria's daughters were silent carriers who passed the disease to the Spanish and Russian royal families. The disease played a role in the origin of the Spanish Civil War; and the tsarina's concern over her only son's haemophilia led to the entry of Rasputin into the royal household, contributing directly to the Russian revolution.