East European Front
The East European Front was the theater of the war that took place in Central and primarily Eastern Europe. The Eastern Front pitted the Russian Imperial Army against those of Germany, Austria-Hungary, and Romania. Although the Western and Eastern Front were separated geographically the two had heavy influence on each other. The Eastern Front's main result was the collapse of the Russian Empire and the subsequent withdrawal from the war entirely. Following the Treaty of Brest-Litovsk the Eastern Front settled down.
Russia had signed several mutual interlocking pacts with the United Kingdom and France ensuring that they would aid each other during a war. However when France invaded Germany Russia refused to invade also, claiming that France had been the aggressor. But when France was forced out of German territory and the Germans launched their own invasion into France Russia mobilized its military to invade Germany.
The Russian plan was to simply invade all three Central nations it bordered simeultaneously. The Tsar divided his forces as following: 400,000 men to Germany, 700,000 men to Austria-Hungary and 200,000 to Romania. He appointed General Samsanov to lead the invasion of Germany, General Ivanov to lead the invasion of Austria-Hungary, and his nephew, Sergei Romanov to invade Romania. The Russians planned three invasions, one of East Prussia, one of Galicia, and one of three Romanian cities. The Tsar predicted that as Germany was tied up in France and Austria-Hungary in Serbia, then the invasion of the two nations would be over within weeks using the massive manpower of Russia. When it came to Romania the Tsar had little respect for the nation, often referring to them as "the smudge to the South."
On August 7th-9th 400,000 soldiers poured into East Prussia, overwhelming the men stationed to defend the province. However despite the extreme numerical superiority the Russians held over Germany they were unable to decisively defeat the Germans. Minor skirmishes broke out, however the knockout blow the Tsar had wanted had yet to arrive. The Russians had their chance at the Battle of Tannenberg but the battle resulted in disaster for the Russians. It resulted in the complete destruction of the Russian Second Army and the subsequent destruction of the Russian First Army. General Samsanov, rather than face the Tsar committed suicide. Following the defeat the entire invasion was called off.
While the defeat at Tannenberg had stopped the Russian invasion of Germany the invasion of Austria-Hungary went incredibly well. Under the command of Ivanov the Russians managed to defeat the Austrians at the Battle of Galicia and ensure their rule over most of their province. Despite the victory however the Germans had mobilized their armies to aid their Austrian-Hungarian allies and a rapid series of counter attacks drove the Russians out of the province. This combined with a Romanian invasion of the Russian motherland led to Russia withdrawing from the country.
The Tsar's nephew Sergei Romanov, a militarily inept and arrogant young man had been appointed to carry out the invasion of Romania. Most of the Russian Court held little respect for Romania, and Sergei had often boasted with 4,000 men he could march across the country. The Russian plan for Romania was to seize the cities of Iasi, Galati and Bacau. This would allow them to establish multiple bases of operations to invade the rest of the nation. The invasion went very well as Romania had stationed most of their military west to counter a Serbian invasion. However Romania was not as militarily backward as the Russians had thought, and merely a week after the Russian invasion the Russian Third Army was defeated at the Battle of the Vulcan Pass. Next Sergei was defeated at the Battle of Iasi, which resulted in the capture of 40,000 troops and Sergei himself. The Tsar, faced with defeats in all three nations ordered a retreat from Romania however before the army could depart they were attacked at the Siege of Bacau, which cooped up 90,000 men in the city. Romania then launched an invasion into Russian territory, relieving pressure along the Austrian and German fronts. The invasion was only stopped after an army of 150,000 was called down from other vital areas to halt the advance.
With several military defeats and food shortages, the Russian people finally revolted against the Tsar in the February revolution and deposed him and his court. The new government signed the Treaty of Brest-Litovsk, ceding massive amounts of territory to Romania, Germany, and Austria-Hungary. This effectively ended all activity on the Eastern Front and allowed the Central Powers to transfer substantial amounts of men to the West to battle the Entente in France.