Generational change has been postponed again in Saudi Arabia, and the kingdom’s succession process is now clear for the foreseeable future. With King Abdullah’s appointment this week of his half-brother Prince Muqrin bin Abdulaziz to the position of second deputy prime minister behind Crown Prince Salman, the inner circle of princes that has run the kingdom for half a century will retain power.

Prince Muqrin, along with King Abdullah and Crown Prince Salman, are all the first-generation offspring of the current kingdom’s founder, King Abdul Aziz. This generation has been in power for nearly 60 years, and the Arab spring isn’t stopping the House of Saud from sticking with its veteran lineup.

The new second deputy prime minister, the slot from which future kings move up in the kingdom, was born Sept. 15, 1945. Educated at the Royal Air Force College in Cranwell, England, Prince Muqrin became a pilot in the Saudi Air Force and then, like many of the royals, he was given a remote province to govern as a young man. In 1999 he was promoted to be governor of Medina province, home of the kingdom’s second holy city. Eight years ago, Abdallah made him head of Saudi intelligence, a job he held until last year, when he was replaced by the former ambassador to Washington, Prince Bandar bin Sultan. Muqrin is an affable and competent leader, but he did not excel as spy chief.

Muqrin has always been one of Abdullah’s favorites and often accompanies the king when he travels for business or for health reasons. Both the king and crown prince are in poor health, with the king making repeated trips to hospitals in the United States in recent years. Salman has been reported to be increasingly ill as well and often not up to the job.

The current Saudi Kingdom is the third state created by the House of Saud. Two earlier kingdoms dating back to 1745 collapsed due to outside pressure and internal divisions created by succession quarrels. All three have been based on a unique partnership between the Saudi royal family and a conservative clerical establishment begun by Muhammad ibn Abd al Wahhab, one of the most important Islamic figures since the earliest days of the faith. The Saud-Wahhab alliance remains crucial to the kingdom’s stability today. Since the kingdom is also home to Islam’s two holiest cities, that partnership has global implications.

Simmering just below the surface is a country perhaps increasingly ripe for revolution. Sixty percent of Saudis are 20 or younger, and most have no hope of a fulfilling job. Seventy percent of Saudis cannot afford to own a home; 40 percent live below the poverty line. The royals, 25,000 princes and princesses, own most of the valuable land and benefit from a system that gives each a stipend and some a fortune. Foreign labor makes the kingdom work; 19 million Saudi citizens share the Kingdom with 8.5 million guest workers. Since the start of the Arab spring, the king has spent $130 billion in new stipends and projects to try to buy off dissent.

Other fault lines are getting deeper and more explosive. Hejazis in the west and Shia in the east resent the strict Wahhabi lifestyle in the Nejd central desert. Gender discrimination, essential to the Wahhabi worldview, is a growing problem, as more and more women become well educated with no prospect of a job. Sixty percent of Saudi college graduates are women, but they are only 12 percent of the workforce. Abdullah recently tried to appease them with appointments to the powerless consultative council, only to provoke outrage from the Wahhabi establishment.

For decades, the kingdom has been blessed with good leadership, and King Abdullah is a progressive by Saudi standards. Muqrin is a good choice for now. But sooner rather than later the third Saudi state will face an unprecedented succession challenge. Since the death of ibn Saud in 1953, succession has moved only among his sons. Now they are all old, ill, and few in number. The kingdom will have to pick a grandson of ibn Saud, and there is no agreed formula for how to do so other than the last of the current line will choose from his own sons. The House of Saud will enter a new world then, without the legitimacy its leaders have enjoyed for a century. History is not encouraging. The second Saudi state fell apart over succession problems in the late 19th century.