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The son of an impoverished Bedouin goat herder, Gaddafi became involved in politics while at school in Sabha, subsequently enrolling in the Royal Military Academy, Benghazi. Founding a revolutionary cell within the military, in 1969 they seized power from the absolute monarchy of King Idris in a bloodless coup. Becoming Chairman of the governing Revolutionary Command Council (RCC), Gaddafi abolished the monarchy and proclaimed the Republic. Ruling by decree, he implemented measures to remove what he viewed as foreign imperialist influence from Libya, and strengthened ties to Arab nationalist governments. Intent on pushing Libya towards "Islamic socialism", he introduced sharia as the basis for the legal system and nationalized the oil industry, using the increased revenues to bolster the military, implement social programs and fund revolutionary militants across the world. In 1973 he initiated a "Popular Revolution" with the formation of General People's Committees (GPCs), purported to be a system of direct democracy, but retained personal control over major decisions. He outlined his Third International Theory that year, publishing these ideas in The Green Book.

How did Gaddafi change the legal system?
he introduced sharia as the basis for the legal system