The Ukrainian War of Independence, also referred to as the Ukrainian–Soviet War in Ukraine, lasted from March 1917 to November 1921 and was part of the wider Russian Civil War. It saw the establishment and development of an independent Ukrainian republic, most of which was absorbed into the Ukrainian Soviet Socialist Republic between 1919 and 1920. The Ukrainian Soviet Socialist Republic was one of the constituent republics of the Soviet Union between 1922 and 1991.