The Vietnam War is commonly considered to have lasted about 20 years, from 1955 to 1975. Most historians date the war from the establishment of the Republic of Vietnam (South Vietnam) and the start of large-scale conflict in 1955–1956, through to the fall of Saigon on April 30, 1975, when North Vietnamese forces captured the South Vietnamese capital and the country was reunified under communist rule. Different sources sometimes give slightly different spans (for example, 1954–1975, or focusing on the main period of heavy U.S. involvement from about 1965–1973), but in everyday usage people usually describe it as running roughly two decades, mid‑1950s to mid‑1970s.