When the Ottomans left at the beginning of World War I in 1915, the British And Ottomans recognised Sheikh Abdullah bin Jassim Al-Thani as the ruler. The Al Thani family had lived in Qatar for 200 years. The 1916 treaty between the United Kingdom and Sheikh Abdullah was similar to those entered into by the British with other Persian Gulf principalities. Under it, the ruler agreed not to dispose of any of his territory except to the U.K. and not to enter into relationships with any other foreign government without British consent. In return, the British promised to protect Qatar from all aggression by sea and to lend their good offices in case of a land attack. A 1934 treaty granted more extensive British protection.

In 1935, a 75-year oil concession was granted to the Qatar Petroleum Company, a subsidiary of the Iraq Petroleum Company, which was owned by Anglo-Dutch, French, and U.S. interests. High-quality oil was discovered in 1940 at Dukhan, on the western side of the Qatari peninsula. However, the start of World War II delayed exploitation of Qatar's oil resources, and oil exports did not begin until 1949.

Qatar (ⁱ/ˈkɑːtɑr/ or ⁱ/kəˈtɑr/;Arabic: قطر‎ [ˈqɑtˤɑr]; local vernacular pronunciation: [ɡɪtˤɑr]), also known as the country or State of Qatar or locally Dawlat Qaṭar, is a sovereign Arab state, located in Western Asia, occupying the small Qatar Peninsula on the northeasterly coast of the much larger Arabian Peninsula. Its sole land border is with Saudi Arabia to the south, with the rest of its territory surrounded by the Persian Gulf. A strait of the Persian Gulf separates Qatar from the nearby island state of Bahrain.

Qatar has been ruled as an absolute monarchy by Al Thani family since the mid-19th century. Formerly a British protectorate noted mainly for pearling, it became independent in 1971, and has become one of the region's wealthiest states due to its enormous oil and natural gas revenues. In 1995, Sheikh Hamad bin Khalifa Al Thani became Emir when he seized power from his father, Khalifa bin Hamad Al Thani, in a peaceful coup d'état. The most important positions in Qatar are held by the members of the Al Thani family, or close confidants of the al-Thani family. Beginning in 1992, Qatar has built intimate military ties with the United States, and is now the location of U.S. Central Command’s Forward Headquarters and the Combined Air Operations Center.