Saudi Arabias Crown Prince Sultan bin Abdulaziz Al Saud died at dawn on Saturday abroad, the countrys royal court said in a statement carried by state media. Sultan, who was thought to be aged about 86, had been in the United States for medical treatment since June. As well as heir to the throne of the Kingdom, he had been defence minister and minister of aviation for about four decades. With deep sorrow and sadness the Custodian of the Two Holy Mosques King Abdullah bin Abdulaziz mourns the death of his brother and his Crown Prince Sultan bin Abdul Aziz Al Saud, who died at dawn this morning Saturday outside the kingdom following an illness, said the statement carried on state news agency SPA and state television. Saudi television broke its schedules early on Saturday to broadcast the Holy Quranic verses accompanied by footage of the Kaaba in the holy city of Makkah. The funeral services will be held in Riyadh on Tuesday, SPA said. Sultan bin Abdul Abdulaziz was a central figure in the worlds top oil exporter who dominated defence policy. A defence minister for almost half a century before becoming crown prince to the Custodian of the Two Holy Mosques King Abdullah bin in 2005, Sultans powerbase lay in his control of the regular armed forces and his status as one of seven full brothers born to the Kingdoms founder King Abdulaziz Ibn Saud. He oversaw a defence spending spree which made the kingdom one of the worlds biggest arms buyers. Sultans death may put in motion for the first time an allegiance council consisting of sons and grandsons of the Kingdoms founder. The council was set up by his half-brother, King Abdullah, to vote on future Kings and their heirs. Prince Sultan, who was born in the mid-1920s, had an intestinal cyst removed in 2005 and had spent several months abroad for treatment. While defence minister, Sultan spent hundreds of billions to modernise the forces of the country, doubling the regular armed forces to more than 100,000 men and buying advanced weapons from all over the world. Western leaders have regularly courted top members of the huge Saudi Royal Family, Prince Sultan in particular, to promote their hardware and secure jobs back home. Minister in first cabinet Sultan was one of a group of ambitious younger princes groomed for high office at an early age. In 1947 Sultans father King Abdulaziz, appointed him governor of the capital Riyadh, a key post now held by his younger brother Prince Salman. He was appointed agriculture minister in the Kingdoms first cabinet in 1953 and was made communications minister two years later. In 1962 he was made minister of defence and aviation, a post he has held for nearly five decades. He had six full brothers, including King Fahd and Prince Nayef, Sultans likely successor as crown prince. When his elder brother Fahd became King in 1982, half-brother Abdullah was named his heir. Sultan became second deputy prime minister and thus front runner to become crown prince after Fahds death. Sultan was keen to maintain close ties with the West, especially the United States, though like the rest of the royal family he distanced himself from the US-led attack on Iraq in 2003. Sultan often travelled across Saudi Arabia to address his soldiers, promising them advanced equipment and assuring them their leaders abided strictly by the Holy Quran and Islamic tradition. He was chairman of the national carrier, Saudi Arabian Airlines (Saudia), since 1965.