People have been living within the area covered by the present-day country of Cambodia at least since the 5th millennium BCE. The ancient Kingdom of Funan occupied a wider area, and it was during that period that the culture became heavily influenced by Hinduism. The state of Chenla then arose. The Khmer Empire had its golden age in the 9th to the 13th centuries, when huge temple complexes were built, most notably Angkor Wat.

Spanish and Portuguese missionaries visited from the 16th century, and Cambodia became a protectorate of France in the 19th century, being ruled as part of French Indochina. Cambodia became an independent kingdom in 1953 under Sihanouk. The Vietnam War extended into Cambodia, giving rise to the Khmer Rouge, which took Phnom Penh in 1975 and carried out a campaign of mass killing. Following an invasion by Vietnam, the Khmer Rouge were deposed and the People's Republic of Kampuchea was established. After years of isolation, the war-ravaged nation was reunited under the monarchy in 1993 and has seen rapid economic progress while rebuilding from decades of civil war.