The Ottoman dynasty did not observe primogeniture (the right of the first-born son to the throne), so in principle the throne was available to any imperial son.

BBC: Uncover the secrets of Topkapi Palace

It is actually a huge museum with the largest collection of imperial treasures in the country, including the superb Dragon Throne the emperor sat on and Buddhas bedecked with almost every precious metal and gemstone imaginable.

BBC: Beijing's once Forbidden City

The obvious solution would be to change the Imperial House Law so that a female could accede to the throne.

CNN: AN HEIR OF CHANGE IN JAPAN

But the drafters of the first Imperial House Law decided not to allow women to ascend the throne in order to preserve the single line that, according to legend, is descended from the sun goddess, Amaterasu Omikami.

CNN: IN HER OWN RIGHT