Cautious pragmatist or intransigent conservative? Two views are emerging of Crown Prince Nayef bin Abdulaziz al-Saud, the new heir to Saudi Arabia's octogenarian King Abdullah and possible future ruler of the world's top oil exporter.
The character of the enigmatic royal will shape the kingdom's approach to a host of challenges at a time of unprecedented change, internally and for the wider Middle East.
Given Abdullah's advanced age and recurring back trouble, Saudi Arabia's new crown prince, even at about 77, is likely immediately to assume a significant role in forming and implementing policy in foreign affairs, the oil market and domestic reforms.
The veteran interior minister has already run the kingdom on a day-to-day basis several times in recent years, meeting foreign leaders and chairing cabinet when both King Abdullah and Crown Prince Sultan were away at the same time.
To Saudi liberals, he represents the stern face of the kingdom's conservative establishment: opposed to any moves toward democracy or women's rights, a supporter of the religious police and the head of an ministry that locks up political activists without charge.
But former diplomats, local journalists and other members of the ruling family who have dealt with the prince paint a softer portrait of a man who has been at the center of Saudi politics for more than three decades.
"Many things are said about Prince Nayef, but I find him to be a very kind man [who keeps] a foot on the ground by meeting people," said Khaled al-Maeena, editor at large of the Arab News daily in Jeddah. "He has the pulse of the nation."
At stake is the direction of a country that dominates world oil markets and wields influence over Muslims through its guardianship of Islam's holiest sites in Mecca and Medina.
Reforms enacted by King Abdullah, who is some 10 years older than Nayef, have focused on boosting job prospects for young Saudis by encouraging the private sector and curbing the influence of a conservative clergy who control education.
Nayef has long been seen as close to the clerics of Saudi Arabia's official Wahhabi school of Islam, which has always backed the ruling Saud family, and is said to have opposed reforms in the past.
"Nayef is widely seen as a hardline conservative who at best is lukewarm to King Abdullah's reform initiatives," said a 2009 US diplomatic appraisal of the prince revealed by WikiLeaks.
"However, it would be more accurate to describe him as a conservative pragmatist convinced that security and stability are imperative to preserve Saud rule and ensure prosperity for Saudi citizens."
Austere desert kingdom
Prince Nayef was born around 1933 in Taif, the mountain town where the royal court repaired each year to escape the stifling summer of the capital Riyadh and the second city Jeddah.
Saudi Arabia had only come into being a year earlier after Nayef's father King Abdulaziz Ibn Saud united Bedouin tribes behind his vision of a pure Islamic state and conquered much of the Arabian Peninsula.
Growing up in the royal court of the 1930s and 1940s, Nayef is of the last generation of Saudis who knew the desert kingdom before oil wealth changed it beyond recognition.
A son of Ibn Saud by his favorite wife Hassa bint Ahmed al-Sudairi, Nayef was one of seven full brothers who were groomed young for high office and formed their own power bloc.
The so-called "Sudairi seven" also included the late King Fahd and Crown Prince Sultan, Riyadh Governor Prince Salman and Nayef's deputy at the Interior Ministry, Prince Ahmed.
Two sons complete the tight family circle at the ministry: Prince Mohammed bin Nayef, the well regarded deputy interior minister in charge of counter-terrorism, and Prince Saud bin Nayef, a former ambassador to Spain.
Named Riyadh governor at the age of 20, Nayef impressed enough to become interior minister by 1975, where he was soon known as an ally of the Wahhabi clerics who supported Saudi rule and had run the palace school of his childhood.
It is this role that has come to define Nayef by giving him responsibility for protecting the kingdom from internal threats – most frequently those posed by Islamic militants.
"Given his paramount concern with maintaining stability, Nayef's instincts tend toward concessions to religious demands, especially on cultural/social issues," said the 2009 US cable.
"This is sometimes misinterpreted as opposition to reform, but more likely stems from a desire to balance competing social forces."
"He has been the interior minister for the last 40 years, so he might have a security mentality," said Khalid al-Dakhil, a political science professor in Riyadh.
"When he becomes the king we should expect him to act differently. He will have a different perspective. He will have different goals. His role will be more inclusive."
As the man to whom the 13 regional governors answer, Nayef personally handles the petitions of individual Saudi citizens on a daily basis, cultivating a network of supporters across a kingdom where tribal and regional ties still matter.
"He has been in touch with the real issues of the people: crime, economics, social problems," said Dakhil.
Nayef is said by princes to be among the kinder members of his royal generation in his treatment of nephews and nieces.
Diplomats, however, describe him as prickly and, the US appraisal finds him stiff, slow and shy, despite occasional flashes of "impish" humor.
"Crown Prince Sultan was a genial fellow, but that's not the image that's accompanied Nayef over the years," said a former diplomat to Riyadh. "I don't think he had that public appeal, but then as minister of interior you don't."
His domestic intelligence service, the Mabahith, has over the years targeted Islamists, liberals and Shias who sought to organize protests or petition the king on democratic reform.
"He talks about development instead of reform," said Mohammed Fahd al-Qahtani, head of the dissident Saudi Civil and Political Rights Association in Riyadh.
"He's the one who threw a lot of people in prison for expressing a desire for reform. The guy is a hard-liner."
Soon after the 11 September 2001 attacks on New York, Nayef was quoted doubting that any Saudi citizens had participated, when it later turned out that 15 of the 19 hijackers were Saudi.
The incident gave him a reputation as anti-Western, but diplomats were impressed with the way his ministry suppressed an Al-Qaeda bombing campaign inside Saudi Arabia a few years later.
Nayef's main foreign policy concerns are said to be the expansion of Al-Qaeda into neighboring countries and the influence of Shia power Iran, which the kingdom has accused of stirring sectarian trouble across the Middle East.
According to the US cable, his distrust of Iran extends to suspicions about the kingdom's own Shia minority, which has pushed for better treatment amid accusations of discrimination.
When Saudi Arabia sent troops to next-door Bahrain in March at the request of a Sunni monarchy that was battling an uprising supported by its Shia majority, it was said by analysts to be partly at Prince Nayef's urging.