The Soviet westward offensive of 1918–1919 was part of the campaign by Soviet Russia into areas abandoned by the Ober Ost garrisons that were being withdrawn to Germany following that country's defeat in World War I. The initially successful offensive against the Republic of Estonia ignited the Estonian War of Independence which ended with the Soviet recognition of Estonia. Similarly, the campaigns against the Republic of Latvia and Republic of Lithuania ultimately failed, resulting in the Latvian–Soviet Peace Treaty and Soviet–Lithuanian Peace Treaty respectively. In Belarus, the Belarusian People's Republic was conquered and the Socialist Soviet Republic of Byelorussia proclaimed.

The Supreme Commander of All German Forces in the East, also known by its German abbreviation as Ober Ost, was both a high-ranking position in the armed forces of the German Empire as well as the name given to the occupied territories on the German section of the Eastern Front of World War I, with the exception of Poland. It encompassed the former Russian governorates of Courland, Grodno, Vilna, Kovno and Suwałki. It was governed in succession by Paul von Hindenburg and Prince Leopold of Bavaria. It was abandoned after the end of World War I.