Saudi Arabia (/ˌsaʊdi əˈreɪbi.ə/ or /ˌsɔːdiː əˈreɪbi.ə/), officially known as the Kingdom of Saudi Arabia (KSA), is the largest Arab state in Western Asia by land area (approximately 2,150,000 km2 (830,000 sq mi), constituting the bulk of the Arabian Peninsula) and the second-largest in the Arab world after Algeria. It is bordered by Jordan and Iraq to the north, Kuwait to the northeast, Qatar, Bahrain and the United Arab Emirates to the east, Oman to the southeast, and Yemen in the south. It is the only nation with both a Red Sea coast and a Persian Gulf coast.
Before the inception of the Kingdom of Saudi Arabia, modern-day Saudi Arabia consisted of four distinct regions: Hejaz, Najd and parts of Eastern Arabia (Al-Hasa) and Southern Arabia ('Asir). The Kingdom of Saudi Arabia was founded in 1932 by Ibn Saud; he united the four regions into a single state through a series of conquests beginning in 1902 with the capture of Riyadh, the ancestral home of his family, the House of Saud. The country has since been an absolute monarchy governed along Islamic lines, namely under the influence of Wahhabism. Saudi Arabia is sometimes called "the Land of the Two Holy Mosques" in reference to Al-Masjid al-Haram (in Mecca), and Al-Masjid an-Nabawi (in Medina), the two holiest places in Islam.
There are 20 million Saudi citizens and 5 million foreigners living in Saudi Arabia. Most Saudis are Sunni Muslims, approximately 23 percent are Wahhabis, especially those living in Najd. With the world's second largest oil reserves and the world's sixth largest natural gas reserves, Saudi Arabia is the world's largest oil exporter. The Kingdom is categorized as a high income economy with the 19th highest GDP in the world. It is a member of Gulf Cooperation Council, Organisation of Islamic Cooperation, G-20 major economies and OPEC. A large portion of the landscape is uninhabitable desert. Its economy is largely backed by its oil industry, which accounts for more than 95% of exports and 70% of government revenue, although at the turn of the 21st century the government has attempted to diversify the economy away from the oil sector.