de facto leader of Libya from 1969 and a controversial Arab statesman.

The son of an itinerant Bedouin farmer, Qaddafi was born in a tent in the Libyan desert. He proved a talented student and graduated from the University of Libya in 1963. A devout Muslim and ardent Arab nationalist, Qaddafi early began plotting to overthrow the Libyan monarchy of King Idrīs I. He graduated from the Libyan military academy in 1965 and thereafter rose steadily through the ranks, all the while continuing to plan a coup with the help of his fellow army officers. Captain Qaddafi seized control of the government in a military coup that deposed King Idrīs in September 1969. Qaddafi was named commander in chief of the armed forces and chairman of Libya's new governing body, the Revolutionary Command Council.

Qaddafi removed the U.S. and British military bases from Libya in 1970. He expelled most members of the native Italian and Jewish communities from Libya that same year, and in 1973 he nationalized all foreign-owned petroleum assets in the country. He also outlawed alcoholic beverages and gambling, in accordance with his own strict Islamic principles. Qaddafi also began a series of persistent but unsuccessful attempts to unify Libya with other Arab countries. He was adamantly opposed to negotiations with Israel and became a leader of the so-called rejectionist front of Arab nations in this regard. He also earned a reputation for military adventurism; his government was implicated in several abortive coup attempts in Egypt and The Sudan, and Libyan forces persistently intervened in the long-running civil war in neighbouring Chad.

From 1974 onward Qaddafi espoused a form of Islamic socialism as expressed in The Green Book. This combined the nationalization of many economic sectors with a brand of populist government ostensibly operating through people's congresses, labour unions, and other mass organizations. Meanwhile, Qaddafi was becoming known for his erratic and unpredictable behaviour on the international scene. His government financed a broad spectrum of revolutionary or terrorist groups worldwide, including the Black Panthers and the Nation of Islam in the United States and the Irish Republican Army in Northern Ireland. Squads of Libyan agents assassinated émigré opponents abroad, and his government was allegedly involved in several bloody terrorist incidents in Europe perpetrated by Palestinian or other Arab extremists. These activities brought him into growing conflict with the U.S. government, and in April 1986 a force of British-based U.S. warplanes bombed several sites in Libya, killing or wounding several of his children and narrowly missing Qaddafi himself.

Libya's purported involvement in the destruction of a civilian airliner over Lockerbie, Scot., in 1988, led to United Nations (UN) and U.S. sanctions that further isolated Qaddafi from the international community. In the late 1990s, however, Qaddafi turned over the alleged perpetrators of the bombing to international authorities; UN sanctions against Libya were subsequently lifted in 2003, and following Qaddafi's announcement that Libya would cease its unconventional-weapons program, the United States dropped most of its sanctions as well. Although some observers remained critical, these measures provided an opportunity for the rehabilitation of Qaddafi's image abroad and facilitated his country's gradual return to the global community. In 2009 Qaddafi was elected chairman of the African Union.