One of the most devout and insular countries in the Middle East, Saudi Arabia has emerged from being an underdeveloped desert kingdom to become one of the wealthiest nations in the region thanks to vast oil resources.
But its rulers face the delicate task of responding to pressure for reform while combating a growing problem of extremist violence.
Named after the ruling Al Saud family, which came to power in the 18th century, the country includes the Hijaz region - the birthplace of the Prophet Muhammad and the cradle of Islam. This fact, combined with the Al Sauds' espousal of a strict interpretation of Sunni Islam known as Wahhabism, has led it to develop a strongly religious self-identity. Saudi Arabia was established in 1932 by King Abd-al-Aziz - known as the Lion of Najd - who took over Hijaz from the Hashemite family and united the country under his family's rule. Since his death in 1953, he has been succeeded by various sons.
The Al Saud dynasty's monopoly of power meant that during the 20th century successive kings were able to concentrate on modernisation and on developing the country's role as a regional power.
It has always been in the ruling family's interests to preserve stability in the region and to clamp down on extremist elements. To this end, it welcomed the stationing of US troops in the country after Iraq's invasion of Kuwait in 1990.
But the leadership's refusal to tolerate any kind of opposition may have encouraged the growth of dissident groups such as Osama Bin Laden's al-Qaeda, which benefited from popular resentment against the role of the US in the Middle East.
After the terrorist attacks on New York and Washington of 11 September 2001 - carried out mainly by Saudi nationals - the Saudi authorities were further torn between their natural instincts to step up internal security and pressure to allow a greater degree of democracy.
In 2003 suicide bombers suspected of having links with al-Qaeda killed 35 people - including a number of foreigners - in the capital Riyadh. Some Saudis referred to the attacks as their own 9/11.
Since then, demands for political reform have increased, as has the frequency of militant attacks, some of them targeted at foreign workers. The security forces have made thousands of arrests.
Municipal elections in 2005 were a first, limited exercise in democracy. But political parties are banned - the opposition is organised from outside the country - and activists who publicly broach the subject of reform risk being jailed.
Saudi Arabia sits on more than 25% of the world's known oil reserves. It is capable of producing more than 10 million barrels per day; that figure is set to rise.
· Full name: Kingdom of Saudi Arabia
· Population: 26.2 million (UN, 2010)
· Capital: Riyadh
· Area: 2.24 million sq km (864,869 sq miles)
· Major language: Arabic
· Major religion: Islam
· Life expectancy: 72 years (men), 76 years (women) (UN)
· Monetary unit: 1 Riyal = 100 halalah
· Main exports: Oil, gas, cereals
· GNI per capita: US $17,700 (World Bank, 2009)
· Internet domain: .sa
· International dialling code: +966
Leaders
Head of State, Prime Minister: King Abdullah Bin-Abd-al-Aziz Al Saud
Saudi Arabia has been ruled since its foundation by the Al Saud dynasty. King Abdullah succeeded the late King Fahd, his half-brother, in August 2005.As crown prince, Abdullah had been the effective ruler of Saudi Arabia since the former king suffered a stroke in the mid-1990s.He became heir to the throne in 1982, commanded the powerful National Guard and was considered to be the most influential figure in the country. He is a former mayor of Mecca. His son, Mutib, is deputy commander of the National Guard. Abdullah is said to have forged alliances with other members of the ruling family to offset the influence of his seven half-brothers. Known as the "Sudayri Seven", they are the most powerful alliance within the ruling family.
He is seen as being untainted by corruption - giving credibility to his drive to stamp it out - and to favour reforms which are balanced with a respect for Saudi traditions.
Regarded in the Arab world as a supporter of wider Arab interests, he has criticised US support for Israel and Israel's occupation of Palestinian territory. At home, he appears to subscribe to the view that granting modest reforms can help prevent potentially explosive tensions from building up.
One of his responses to the Arab Spring has been to use financial sweeteners in an effort to keep the Saudi people happy. He has also promised Saudi women that they will eventually get the vote.
King Abdullah is believed to have been born in 1924. He received a traditional religious education and is close to the Saudi tribal way of life, often spending periods of time in the desert. However, he has never shared the severely puritanical view of Islam of his country's Wahhabi religious establishment.
Interior Minister Prince Nayef bin Abdulaziz al Saud was named as heir to the throne, following the death of Sultan bin Abdul Aziz in October 2011.
