By Gerald Butt
Middle East analyst
Sultan is widely seen as the second in line for the Saudi thrown
Prince Sultan, second deputy prime minister and minister of defence and aviation, is one of the senior members of the ruling family who has generally favoured close ties with the United States - his son Bandar is the Saudi ambassador in Washington.
But of late, Prince Sultan has been critical of American foreign policy in the aftermath of the September 2001 bombings and, in particular, the strong criticism directed at Saudi Arabia.
Prince Sultan is chairman of the Higher Council for Islamic Affairs, an organisation that provides funds for Muslim communities around the world.
Because of this role, his name has been raised in connection with claims that Saudi money has been paid to Islamic charities with alleged links to terrorist groups - allegations strongly denied by the prince.
Prince Sultan was born in Riyadh in 1928.
He is one of the seven male offspring of King Abd-al-Aziz's favourite wife, Hassa bint Ahmad al-Sudayri - the Sudayri seven, as they are known.
He received a traditional education in his father's court and made his first major appearance on the public stage in 1947 when he was appointed governor of Riyadh.
In 1953 he became minister of agriculture, and two years later he was handed the communications portfolio.
Development and conservation
Prince Sultan has held his current post in the Ministry of Defence and Aviation since 1963.
In this capacity he has been closely involved in the development expansion of the Saudi national airline, Saudia, and the construction of the rail link between Dammam on the Gulf coast and Riyadh.
In his private life Prince Sultan has an interest in nature and conservation. He was the founder, in 1986, of the Saudi National Commission for Wildlife Conservation.
In 1982, when King Fahd's reign began, Prince Sultan was appointed second deputy prime minister.
The expectation is that he will take the title of crown prince when Prince Abdullah becomes king.
BBC Monitoring, based in Caversham in southern England, selects and translates information from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages.