WW1 on the eastern front was completely different to fighting on the western front. Beginning with the Russian invasion of East Prussia in early 1915 the war was to feature constant flanking attempts and extremely mobile warfare. During the Russian invasion of East Prussia, an enormous number of almost 600,000 Russians marched into Germany looking to seize Allenstein, then move through to Danzig. Due to some excellent German manoeuvring however, a far smaller force was able to use the railway lines in East Germany to sweep around behind the Russians and completely cut them off, resulting in the loss of the Russian army.

Due to the massive size of Russia and inability to fortify all ground, the war followed a pattern of attack, take huge amounts of ground, get counter attacked before being able to consolidate ground, enemy takes huge amounts of ground, counter attack and so on.

The War against the Russians was far more decisive than on the Western front. The German army did end up taking huge amounts of ground, taking all the ground up to Riga in Lithuania. Eventually though they had such an impact on the entire Russian nation that they were able to push their victory terms onto the Russians. When the Russians surrendered in Early 1918 they gave to the Germans what is now, Belarus, Ukraine, Lithuania, Estonia, Latvia and Poland.