Crown prince The heir apparent to Saudi throne, Prince Sultan bin Abdul-Aziz al-Saud, one of the kingdom's most powerful princes, served as defence minister. Prince Sultan was the second son of the elite 'Sudairi seven' — seven full brothers by the favourite wife of King Abdul Aziz al-Saud, who founded the kingdom in 1932 - now responsible for 25 per cent of the world's oil. He became governor of Riyadh in 1947 and oversaw the Arabian American Oil Company's construction of a rail link between Dammam in the eastern province and Riyadh. Prince Sultan became agriculture minister helping to settle Bedouin on modern farms, and was considered hardworking and pugnacious. Appointed as defence minister and head of civil aviation in 1963 Prince Sultan made most of the major decisions including establishing a close alliance with the United States during his tenure. As defence minister he spent hundreds of billions of dollars on modern weapons, mostly from American companies, and built a string of vast military cities that ring the interior of kingdom, including one named after him in Kharj, outside Riyadh. As one of the staunchest supporters of the kingdom's close alliance with the United States, Prince Sultan endorsed King Fahd's decision to allow 500,000 American troops into Saudi Arabia to free Kuwait from Iraq, and played a pivotal behind-the-scenes role in the prelude to the 1991 Persian Gulf War. Saudis of all stripes often use the same three words to describe him: charming, charitable and corrupt. Prince Sultan grew extremely rich in the job, buying mega-toys like the Al Salamah, one of the largest private yachts in the world, more than 450 feet long with a crew of nearly 100. He was accused of skimming large commissions off weapons purchases and obtaining vast tracts of public land. Some Saudis, including fellow princes, reportedly described him as 'Nahhab Wahhab,' or the charitable thief, not resenting him for it because he spread the money so widely. Prince Sultan was known for his charitable donations, and built a sprawling humanitarian city near Riyadh for rehabilitation and treatment for the elderly. Becoming the crown prince in 2005, Prince Sultan who was battling colon cancer since 2004, passed away at a New York's hospital. He was born in Riyadh.