Saudi Crown Prince Sultan bin Abdulaziz Al Saud has died, a State Department official said on Friday. Crown Prince Sultan, 81, was the deputy minister of aviation and defense, and was one of the key figures in Saudi Arabia. He has had various medical issues in recent years. In 2009, he was in New York for surgery for an undisclosed illness. At the time, there was speculation that the illness was serious. He has also flown to Morocco for additional medical treatments.