Population: Sunni Muslim 95%, Shia Muslim 5%

Islam and the state: Saudi Arabia has central role in the Islamic world because it is home to Mecca and Madinah, Islam's two holiest sites. Wahhabism, a conservative interpretation of Sunni Islam, has been a cornerstone of the royal family's legitimacy. Saudi Arabia practices a highly conservative interpretation of Sharia law. The kingdom is widely criticised for its human rights abuses.

Militant Islam: Osama Bin Laden was born into a prominent Saudi family. Fifteen of the 19 men suspected of carrying out the 11 September suicide attacks on New York and Washington were Saudis. The kingdom is currently facing a series of attacks from armed militants opposed to the Saudi royal family. Saudi officials say the attackers are linked to al-Qaeda. Wahhabism as taught in Saudi Arabia's universities and mosques has provided ideological backing for radical Islamic groups across the world. Saudi religious charities, some linked to the government, have been found to provide funding for militant Islamic groups.