Saudi Arabia, officially known as the Kingdom of Saudi Arabia (KSA), is the largest Arabstate 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 ofEastern 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 ofWahhabism. Saudi Arabia is sometimes called "the Land of the Two Holy Mosques" in reference to Al-Masjid al-Haram (in Mecca), andAl-Masjid an-Nabawi (in Medina), the two holiest places in Islam. The Kingdom has the total population of 28.7 million. Saudi Arabia is the world's dominant oil producer and exporter while it controls world's second largest hydrocarbon reserves. Backed by the energy reserves, the kingdom is categorized as a high income economy and is part of the G-20 major economies, the only Arab country to be part of the latter. The kingdom is characterized as a developed country while ranking very high on human development index, politically it is ranked as an authoritarian regime, it also has the fourth highest military expenditure in the world. It is an active member of Gulf Cooperation Council, Organisation of Islamic Cooperation and OPEC.