Not sure but if I had a guess it probably was the soviet union (russia)
Through 1944 that would be Germany, after that Russia controlled and held eastern Europe for decades.
The war on the Eastern Front ended with the signing of the Treaty of Brest-Litovsk in March 1918, following the Bolshevik Revolution in Russia. The treaty marked Russia's exit from World War I and resulted in significant territorial losses for Russia, ceding land to Germany and its allies. The collapse of the Eastern Front allowed Germany to concentrate its forces on the Western Front before the eventual defeat of the Central Powers later in 1918.
the German plans to invade France through belgium and overwhelm them before russia mobilized on the eastern front (used in world war one)
To water it down as much as possible, there were two main conflicts World War II was fought over: 1) Who would dominate Europe, and then the world, and . . . 2) Who would dominate the Pacific, and then the world.
Eastern Europe
World War II deaths and persecutions under Stalin
Russia is the largest country in eastern Europe. It is also the largest country in the world.
russia
The largest populated country in Eastern Europe is Russia.
Russia has the largest land area of any country in the Eastern Hemisphere. (Russia is also the largest country by land area in the world.)
Russia and Eastern Eurpoe
Russia has the most land area in the eastern hemisphere. It is the largest country in the world by land area and spans both the eastern and western hemispheres.
The main fronts in World War I were in France and in Russia. The Western Front was in France and the Eastern Front was in Russia.
Russia gained control of Eastern Europe. -Blissful
It's in Eastern Europe, Just West of Russia.
Most Russians live in western Russia, particularly in cities such as Moscow and St. Petersburg. Eastern Russia, which includes regions such as Siberia and the Russian Far East, is more sparsely populated.