The death of the hardline heir to the Saudi Arabian throne could mean more rapid reform in the Islamic kingdom.
Crown Prince Nayef bin Abdul-Aziz al-Saud, has died just eight months after becoming heir to 89-year-old King Abdullah. State TV said Nayef died in Geneva, where he had been receiving treatment for an unknown illness.
The 78-year-old, who also headed the Interior Ministry, was known as a reactionary whose views on issues such as women driving differed from those of the King.
His death underlines the age of the senior office-holders in the royal family, all of whom are sons of Abdul-Aziz Ibn Saud, who founded the desert kingdom in 1932.
Defence Minister Prince Salman, 76, has long been regarded as the next most senior prince after Nayef. He is seen as a supporter of King Abdullah's cautious reforms.