21st Rifle Division (Soviet Union)

The 21st Rifle Division (21-я стрелковая дивизия) was an infantry division of the Bolshevist Russia and then the USSR, active between 1918 and 1945. Organised during the Russian Civil War on September 3, 1918 out of several smaller partisan detachment of Perm Governorate. Soon it was reinforced with a single artillery battery from Sankt Petersburg and two Workers' Brigades from the Arkhangelsk Front. Initially known as the 5th Ural Infantry Division, it was renamed on March 19, 1919.

Commanded by Ivan Smolin, the division took part in the ill-fated Russian summer offensive of 1920, which ended with the Battle of Warsaw. Despite initial successes, the division was ultimately defeated in the Battle of Radzymin and annihilated in the following days.

Reformed in Russia, it was activated on June 22, 1941 at Spassk-Dalny in the Far East. It was part of 26th Rifle Corps, 1st Red Banner Army. Following the German invasion of the Soviet Union and a string of Soviet defeats early in the war, on September 11, 1941 the division was transported to Ivanovo, where it received its heavy equipment and assumed defensive positions along Svir River. Not attacked directly by German forces, the division remained in the area until March 1944, when it was moved to the Arctic theatre of operations, to Kandalaksha. As part of the 19th Army it took part in defeating a group of German forces in the area of Alakurtti and reached the pre-war Soviet-Finnish border.

In January 1945 it was transferred to Hungary, to defend against a German attack across the Leitha. Surrounded on January 20 in the vicinity of Aba and Jakabszállás, the following day it broke through and reached friendly lines. On January 28 it received reinforcements and took part in the Soviet counter-offensive between Leithe and Danube.

It later took part in defence against the Balaton Offensive and then the Vienna Offensive, operating from the town of Nagykanizsa.