The 16th Army was a field army of the Red Army during the Russian Civil War era. It was originally formed as the Western Army (Russian: Западная Армия) on November 15, 1918, by the Russian SFSR for the purpose of recovering territories lost by the Russian Empire during the First World War and establishing Soviet republics in those territories. The Western Army engaged various local forces from the Baltic States, Belarus, Poland and Ukraine, and its actions contributed to starting the Polish–Soviet War of 1919–1920. The army fought in the Polish–Soviet War under the command of Nikolai Sollogub and advanced westwards into Poland in July 1920 before being thrown back during the Battle of Warsaw in August. The army retreated east into Belarus and was disbanded in May 1921.