Western Army (Западная Армия) was created on November 15, 1918 by RSFSR with the purpose of moving westwards after the retreating German forces in order to establish Soviet governments in Belarus and Ukraine. It was also known as the 16th army. The Western Army advance would lead to the Polish-Soviet War of 1919-1920.

History

After the Treaty of Brest-Litovsk the newly-established Russo-German border line from the Russian side was controlled by the so-called Western Section of Curtain Troops (Западный участок отрядов завесы), or simply the Western Curtain. The curtain was a sparse and heterogeneous set of detachments Its commander was Vladimir Egoryev. (His official rank was "military leader" (военный руководитель), since he was a former Tsarist general) The Western Curtain covered over 800 kilometres along the line Nevel -Polotsk-Senno -Orsha-Mogilev-Zhlobin-Gomel-Novy Oskol . Eventually the Western Curtain was arranged into 7 main detachments with 20,000 personnel. This number was far from being sufficient in the case of any battle. Moreover, part personnel was moved to other bottlenecks of the Russian Civil War.

Eventually the recruitment to the Red Army allowed to reorganize the detachments of the "Curtain" into regular divisions, and the "Curtain" was reorganized into the Western Defence Region (Западный район обороны). It was created by the Revolutionary Military Council order #3/2 September 11, 1918. The Region extended from Petrograd to the Western edge of the Southern Front , commander Andrey Snesarev (Андрей Евгеньевич Снесарев).

Soon after the annulling of the Treaty of Brest-Litovsk by the Soviet side, the Western Defense region was transformed into the Western Army (November 15, 1918), garrisoned in Smolensk. It was composed of: Pskow-Lithuanian Infantry Division, 17th Witebsk Riflemen Division, 'Western' Riflemen Division and and grouoed units of 2 Area of Front Defense. Near the end of 1918 the strenght of the Western (16th) Army was around 19,000, with little artillery or cavalry (8 guns and 261 horses total). Over the next few month the Army grew to 46,000 strenght. It was considered by the Soviet High Command to be one of the least important armies in that period.

Immediately after its formation, on November 17, 1918 the Western Army started the bloodless advance after the retreating German forces in the directions of Belarus and Ukraine. The westward operation had a goal to take control over the territory abandoned by the German East Army retreating from the Ober-Ost theatre of operations. Later Soviet Western Army engaged various self-defence and militia groups from Bielorussia, Lithuania, Poland and Ukraine. Among scores of little battles, the most important would be the Battle of Bereza Kartuska from February 14, which would signal the unitentional start of what would become, over the coming months, perhaps the most important war of the interbellum period - the Polish-Soviet War.