The Battle of Tannenberg was an engagement between the Russian Empire and the German Empire in WWI. The war was fought in Stebark, Poland. The Russians used their First and Second Armies and Germany used their eighth army. The battle took place on August 17th and ended around September 2, 1914. It all started when two Russian armies invaded German East Prussia in August of 1914. Russia's first army was led by Rennenkampf, and its second army was led by Samsonov. On August 20th, Rennenkampf's army defeated eight divisions of German's eight army on the eastern front. By the time this happened, Samsonov's army had already crossed through southern East Prussia to threaten the German rear. When faced with the attack, Germans 8th army approved the
