The Eastern Front was a theatre of war during World War I in Central and, primarily, Eastern Europe. The term is in contrast to the Western Front. Despite the geographical separation, the events in the two theatres strongly influenced one another. In Russian sources, the war was sometimes called the Second Fatherland War.
The front in the east was much longer than that in the west. The theatre of war was roughly delimited by the Baltic Sea in the west and Minsk in the east, and Saint Petersburg in the north and the Black Sea in the south, a distance of more than 1,600 kilometres (990 mi). This had a drastic effect on the nature of the warfare. While World War I on the Western Front developed into trench warfare, the battle lines on the Eastern Front were much more fluid and trenches never truly developed. This was because the greater length of the front ensured that the density of soldiers in the line was lower so the line was easier to break. Once broken, the sparse communication networks made it difficult for the defender to rush reinforcements to the rupture in the line, mounting rapid counteroffensives to seal off any breakthrough. In short, on the Eastern front the side defending did not have the overwhelming advantages it had on the Western front. However, as in the Napoleonic Wars and World War II, Russian forces were familiar with their own ground which provided a natural advantage for the Russian emperor's land forces.
At the outbreak of the war, Tsar Nicholas II appointed his cousin, Grand Duke Nicholas as Commander-in-Chief of the Imperial Russian Army. On mobilization, the Russian army totaled some 1.2 million men under arms, including 70 infantry and 24 cavalry divisions with nearly 7,900 guns (7,100 field guns, 540 field howitzers and 257 heavy guns). Divisions were allocated as follows: 32 infantry and 10.5 cavalry divisions to operate against Germany, 46 infantry and 18.5 cavalry divisions to operate against Austria-Hungary, 19.5 infantry and 5.5 cavalry divisions for the defence of the Baltic Sea and the Black Sea littorals, and 17 infantry and 3.5 cavalry divisions were to be transported in from Siberia and Turkestan.
The war in the east began with the Russian invasion of East Prussia and the Austro-Hungarian province of Galicia. The first effort quickly turned to a defeat following the Battle of Tannenberg in August 1914. The second incursion was completely successful, with the Russians controlling almost all of Galicia by the end of 1914. Under the command of Nikolai Ivanov and Aleksei Brusilov, the Russians won the Battle of Galicia in September and began the Siege of PrzemyÅ›l, the next fortress on the road towards KrakÃ³w.
This early Russian success in 1914 on the Austro-Russian border was a reason for concern to the Central Powers and caused considerable German forces to be transferred to the East to take pressure off the Austrians, leading to the creation of the new German Ninth Army. At the end of 1914 the main focus of the fighting shifted to central part of Russian Poland, west of the river Vistula. The October Battle of the Vistula River and the November Battle of ÅÃ³dÅº brought little advancement for the Germans, but at least kept the Russians at a safe distance.
The Russian and Austro-Hungarian armies continued to clash in and near the Carpathian Mountains throughout the winter of 1914â€“1915. Przemysl fortress managed to hold out deep behind enemy lines throughout this period, with the Russians bypassing it in order to attack the Austro-Hungarian troops further to the west. They made some progress, crossing the Carpathians in February and March 1915, but then the Germans sent relief and stopped further Russian advance. In the meantime, Przemysl was almost entirely destroyed and the Siege of Przemysl ended in a defeat for the Austrians.