King Abdullah, who succeeded his half brother King Fahd on Monday, is a popular leader who has been the kingdom's effective ruler for 10 years and is the main force behind an unprecedented reform drive.
The 81-year-old Abdullah, sticking to tradition, immediately appointed his half brother, Defense Minister Prince Sultan, 77, as his crown prince and successor.
But the first change in the throne in 23 years uncorks a jockeying for position in the line of succession among the next generation, made up of dozens of Western-educated, technology-savvy princes who can take the kingdom into the 21st century.
The choice of Sultan is a sign that deep-rooted reform -- which diplomats and analysts say is the only way the ruling Al Saud dynasty can ensure its survival -- has been placed on the back burner as Abdullah pursues change at his own pace.
Sultan -- like Abdullah, Fahd and all the 42 sons of Saudi Arabia's founder, Abdul-Aziz -- had only a rudimentary education in the era before oil wealth flooded the kingdom. Sultan is likely to appease the religious establishment, which gives the monarchy its legitimacy, rather than continue to reform its institutions.
The newer generation grew up in riches, with greater technology and contact with the West -- typified by Sultan's son, Prince Bandar, who was Saudi Arabia's urbane ambassador to the United States until he stepped down to return home two weeks ago.
Saudi Arabia faces the challenges of liberalizing its ailing economy and satisfying many Saudis' desire for greater freedom and more say in politics. It must tame the radical religious elements so the royal family's role as guardian of Islam's holy places will not be challenged.
And, it must battle violent extremists who many people believe have been encouraged by the preachings of the religious establishment and its strict Wahhabi Muslim philosophy.
Unlike Fahd, Abdullah did not see the fate of his kingdom intertwined with the decades-old alliance with the United States. But once he became the kingdom's de facto leader after Fahd's 1995 stroke, he was pragmatic enough to preserve close ties with the United States.
He understood he had to initiate changes in his country after the Sept. 11 attacks, carried out by 19 Arab hijackers, 15 of them Saudi. U.S. and Western pressure on Saudi Arabia to reform was immense.
After al-Qaida-linked radicals began strikes inside the kingdom in May 2003, the Sauds realized their monarchy was at stake, and Abdullah launched a crackdown, arresting or killing dozens of militant leaders.
Following the May attacks, Saudi Arabia announced the country's first elections -- a vote on municipal councils -- and held the polls in the first three months of 2005.
The kingdom put new restrictions on Islamic charities to ensure donations do not end up funding terror. And it has notified mosque preachers to spread a moderate message and speak out against terrorism and extremism.
When the relationship was strained over the Sept. 11 attacks, especially following accusations by some U.S. officials that Wahhabism encourages terrorism, Abdullah worked to mend ties. He visited President Bush twice -- in 2002 and 2005 -- at his ranch in Crawford, Texas, and officials on both sides have said the tensions are over.
But his relations with Washington were not always smooth.
In 1997 he is reported to have told American Secretary of State Madeleine Albright that the American troops stationed in Saudi Arabia since ousting Iraqi forces from Kuwait in 1991 were becoming a liability.
That boosted his standing among Saudis, who admired him for trying to stand up to the United States and widely resented the presence of thousands of U.S. troops on their land. The last troops were withdrawn following the 2003 war on Iraq.
The plight of Palestinians has also been one of Abdullah's top concerns, and he has been a critic of Washington's support for Israel. He presented a peace plan in 2002 that said Arab states were prepared to establish full diplomatic relations with Israel in exchange for its full withdrawal from occupied Arab territory, the creation of a Palestinian state and settlement of the Palestinian refugee issue.
Inside the ruling family Abdullah is handicapped by his lineage, which could weaken his monarchy. He is half brother to the influential elite of seven princes known before Fahd's death as the Sudairi 7, after their mother's maiden name. They include the late King Fahd, Pricen Sultan, Interior Minister Prince Nayef, and Prince Salman, the powerful governor of Riyadh.
They are among the 42 sons of King Abdul-Aziz ibn Saud, who conquered his rivals and welded the disparate regions of the Arabian peninsula into an eponymous state in 1932.
Abdullah's mother was from the Shammar tribe. He was born in Riyadh in 1924, but the exact date is unknown because no exact records of births or deaths were kept at the time in what was then an impoverished desert land.
Abdullah's selection as crown prince in 1982 was challenged by Prince Sultan, who wanted the title for himself. But the sons of Abdul-Aziz closed ranks when the issue was decided, aware that a direct confrontation with Abdullah could tear the family apart.
However, a foretaste of the opposition Abdullah could face as king came when Fahd briefly handed over the country's reins to his half-brother after suffering a stroke in 1995. In the seven weeks he held power, Abdullah refused to let the royals -- believed to number close to 7,000 princes and princesses -- dip into the state coffers.
Finally, the Sudairis pressured Fahd to take back power, fearing the loss of their privileges.
But the brief period on the throne gave Abdullah confidence and experience. With Fahd too sick to govern, Abdullah resumed the role as de facto ruler.
Abdullah himself suffered a stroke in 1995, but appears to be in good health. He's suffered from a stutter since childhood.
He sports a goatee and moustache and has a passion for the simple bedouin pleasures of horse riding and falcon hunting. He spends at least a month every year hunting in Morocco in a special high-tech desert encampment.
His reputation as a fair and unpretentious man have won him unswerving loyalty of the National Guard, which he has led since 1962. He built up the once largely ceremonial unit into a modern 75,000-strong force as a counterweight to the army. It protects the royal family and is the foundation of his power.
For most Saudis, Abdullah has become a larger-than-life leader.
Part of the widely told folklore about him is a fable he reportedly told Albright when she was visiting the kingdom in 1997 for permission to strike Iraq.
He is said to have told her the story of a shepherd who hired dogs to help guard his flock from wolves, a reference to U.S. troops stationed in Saudi Arabia.
The dogs became too expensive to maintain, and the shepherd had to kill some of his sheep to feed them. In the end, he decided to get rid of the dogs and try to handle the wolves himself.
Abdullah's own strict upbringing is exemplified by the three days he spent in prison as a young prince, a punishment by his father for not having given up his seat for a visitor, a severe violation of bedouin hospitality.
Abdullah has married more than 30 times and usually keeps four wives at a time, as allowed by Muslim law. His wives have included Syrian, Palestinian and Moroccan women. He is related by marriage to King Hussein of Jordan.
"Absolute faith corrupts as absolutely
as absolute power."