RIYADH Saudi Arabia's Defence Minister Prince Salman bin Abdulaziz, seen as more moderate than his hawkish brother Crown Prince Nayef who died on Saturday, is likely to be anointed heir to the throne of the world's top oil exporter.
Although the choice of a new crown prince must be confirmed by a family allegiance council, analysts said it would be highly surprising if Salman, now 76, was passed over.
"The most obvious candidate is Prince Salman," said Saudi politics professor Khalid al-Dakhil.
If appointed, he is likely to shoulder much of the burden of state immediately, given that King Abdullah is already 89.
An imposing figure, Salman controls one of the Arab world's largest media groups.
He believes that democracy is ill-suited to the conservative kingdom and advocates a cautious approach to social and cultural reform, according to a 2007 U.S. diplomatic cable released by WikiLeaks.
A familiar figure to the kingdom's top ally - the United States - he is someone with whom Washington would be comfortable doing business.
"It appeared to me he had a good handle on the delicate balancing act he had to do to move society forward while being respectful of its traditions and conservative ways," said Robert Jordan who was U.S. ambassador in Riyadh from 2001-03.
"He doesn't blindly accept everything the United States says, but at the same time he understands the importance of the relationship, which goes beyond oil," Jordan added.
After nearly 50 years as governor of Riyadh province, Prince Salman now controls the big-spending Defence Ministry.
The ministry has long used arms purchases to turn the Saudi armed forces into one of the best equipped in the Middle East and to bolster ties with allies such as the United States, Britain and France.
Since being named defence minister last year, he has been to both Washington and London, meeting President Barack Obama and Prime Minister David Cameron.
A family insider, Salman has been part of the inner circle of the al-Saud ruling family, which founded and still dominates the desert kingdom in alliance with conservative religious clerics, for decades.
In a royal family that bases its right to rule on its guardianship of Islam's holiest sites in Mecca and Medina, Salman is reputed to be devout but relatively outward-looking.
"He's not extravagant, whether in his personal life or professionally," said Khaled Almaeena, editor-in-chief of Saudi Gazette, who has known Salman personally for more than three decades.
"He's not a spendthrift and makes sure public money is spent well on projects. If you go to his office he's there every morning meeting people. He has a knack of remembering people and events... He has travelled abroad a lot and is very well read and is very well versed in dealing with the tribes."
From 1962 until last year, Salman served as governor of Riyadh, a position that meant he has had more to do with foreign governments than many senior royals.
That role saw him arbitrating disputes between quarreling members of the ruling family, putting him at the centre of the kingdom's most important power structure.
In a meeting with the U.S. ambassador in March 2007, described in a cable released by WikiLeaks, Salman said the social and cultural reforms instigated by King Abdullah had to move slowly for fear of a conservative backlash.
He also argued against the introduction of democracy in the kingdom, citing regional and tribal divisions, and told the ambassador that a solution to the Palestinian-Israeli conflict was necessary for Middle East stability.
"He is liberal in his personal life and moderate in politics, he can't be called a liberal because he holds some conservative values," said a source close to the Saudi royals.
"He is a very balanced character, so moderate is the best word to describe him," the source added.
With his strong bearded features, Salman is the prince who is said to more closely resemble his father, King Abdulaziz Ibn Saud, than any of his brothers.
Backed by a small group of followers inspired by an austere vision of Islam, Ibn Saud recaptured his family's old stronghold of Riyadh in 1902, launching a three-decade campaign of conquest that carved out the modern borders of a kingdom founded in 1932.
Salman is one of the so-called "Sudairi seven" - the brothers born to Ibn Saud by his favorite wife Hassa bint Ahmed al-Sudairi.
His full brothers in a family of more than 30 half-brothers include the late King Fahd and Crown Prince Sultan, Nayef and Prince Ahmed, the deputy interior minister.
Salman was born in 1935 in Riyadh, then a mud brick oasis deep in the interior of a new kingdom that had not yet discovered oil, depending instead on revenue from pilgrims to Mecca and Medina, date farming and camel herding.
Yet one son, Prince Sultan bin Salman, became the first Arab astronaut, flying on the U.S. space shuttle Discovery in 1985.
Prince Sultan is now the kingdom's tourism minister while another son, Prince Abdulaziz, is the deputy oil minister.
In his five decades administering Riyadh and its surroundings, Salman oversaw the development of the capital from a large desert town into a metropolis of 4.6 million people.
He was taught in the "princes' school" set up in Ibn Saud's palace by the imam of the Grand Mosque of Mecca, signaling the importance that Ibn Saud attached to the centrality of pure Islamic belief in the kingdom he created.
(Reporting by Angus McDowall; Additional reporting by Amena Bakr; Editing by Sami Aboudi, Samia Nakhoul and Andrew Osborn)