DUBAI - Saudi Arabia's Crown Prince Sultan bin Abdulaziz Al Saud died at dawn on Saturday, the country's royal court said in a statement carried by state media. Sultan, who was thought to be aged about 86, had been heir to the throne of the Kingdom since 2005 but was a central figure in Saudi decision making since becoming defence minister in 1962. “With deep sorrow and sadness the Custodian of the Two Holy Mosques King Abdullah bin Abdulaziz of Saudi Arabia mourns the death of his brother and his Crown Prince Sultan, 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. Sultan's health had declined in recent years and he spent long periods outside the kingdom for medical treatment. King Abdullah is now expected to call to session an untested “Allegiance Council” to appoint his new heir, widely expected to be Prince Nayef, the veteran interior minister. Set up in 2006 soon after King Abdullah became King, the Allegiance Council is tasked with voting to approve the monarch's choice of crown prince or nominating its own choice instead. Because some members are thought to be travelling, the council might not be able to convene to approve a new crown prince for some days. “The succession will be orderly,” said Asaad Al Shamlan, a professor of political science in Riyadh. “The point of reference will be the ruling of the Allegiance Council. It seems to me most likely Nayef will be chosen.” Prince Nayef has been interior minister since 1975 and was appointed second deputy prime minister in 2009, a position usually given to the man considered third in line to rule. Prince Nayef has managed the Kingdom's day-to-day affairs during absences of both the King and Crown Prince. 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. Funeral services will be held in the Saudi capital Riyadh on Tuesday, SPA said.