Saigon was the capital city of South Vietnam during the Vietnam War. Initially settled by Cambodians, Saigon has for centuries been a major port city in Southeast Asia. It is located about 45 miles up the Ben Nghe River, or Saigon River, from the South China Sea. The French began using the name Saigon in 1861 when they moved into the city and geared up for their takeover of the rest of the country. By 1980, the city had a population of almost two million people concentrated into 27 square miles, making it one of the most population-dense areas in the world. Neighboring Saigon is the city of Cholon, composed mostly of ethnic Chinese. In 1956, Ngo Dinh Diem named Saigon the capital city of South Vietnam. When North Vietnamese and Vietcong forces overran Saigon in 1975, they renamed it Ho Chi Minh City.