Saudi Arabia, officially the Kingdom of Saudi Arabia, is a sovereign Arab state in Western Asia constituting the bulk of the Arabian Peninsula. With a land area of approximately 2,150,000 km², Saudi Arabia is geographically the fifth-largest state in Asia and second-largest state in the Arab world after Algeria. Saudi Arabia 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 to the south. It is separated from Israel and Egypt by the Gulf of Aqaba. It is the only nation with both a Red Sea coast and a Persian Gulf coast and most of its terrain consists of arid desert and mountains.
The area of modern-day Saudi Arabia formerly consisted of four distinct regions: Hejaz, Najd and parts of Eastern Arabia and Southern Arabia. 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. Saudi Arabia has since been an absolute monarchy, effectively a hereditary dictatorship governed along Islamic lines.