The Eastern Front of World War II was a theatre

Theater (warfare)

In warfare, a theater, is defined as an area or place within which important military events occur or are progressing. The entirety of the air, land, and sea area that is or that may potentially become involved in war operations....

 of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 between the European Axis powers

Axis Powers

The Axis powers , also known as the Axis alliance, Axis nations, Axis countries, or just the Axis, was an alignment of great powers during the mid-20th century that fought World War II against the Allies. It began in 1936 with treaties of friendship between Germany and Italy and between Germany and...

 and co-belligerent

Co-belligerence

Co-belligerence is the waging of a war in cooperation against a common enemy without a formal treaty of military alliance.Co-belligerence is a broader and less precise status of wartime partnership than a formal military alliance. Co-belligerents may support each other materially, exchange...

 Finland

Finland

Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 against the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

, and some other Allies

Allies of World War II

The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...

 which encompassed Northern

Northern Europe

Northern Europe is the northern part or region of Europe. Northern Europe typically refers to the seven countries in the northern part of the European subcontinent which includes Denmark, Estonia, Latvia, Lithuania, Norway, Finland and Sweden...

, Southern

Southern Europe

The term Southern Europe, at its most general definition, is used to mean "all countries in the south of Europe". However, the concept, at different times, has had different meanings, providing additional political, linguistic and cultural context to the definition in addition to the typical...

 and Eastern Europe

Eastern Europe

Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...

 from 22 June 1941 to 9 May 1945. It was known by many different names depending on the nation, notably the Great Patriotic War in the former Soviet Union, while known in Germany as the Eastern Front , the Eastern Campaign or the Russian Campaign .

The battles on the Eastern Front constituted the largest military confrontation in history.