The Battle of Tannenberg was a four day battle between the Russian army, led by Alexander Samsonov, and the German army, led by General von Hindenburg. The Russians agreed to help relieve the French, who were under attack by the Germans, by attacking them in East Prussia. Two Russian armies invaded Germany East Prussia and were to attack Germany from the east and south. The attack began in Gumbinnen when Rennekamfp's First Army defeated eight divisions of the German Eighth Army while Samsonov's forces crossed the southern frontier of East Prussia. Commander of the Eighth Army, General von Hindenburg, agreed to attack Samsonov's left flank. The Germans also intercepted an uncoded Russian message indicating that Rennekamfp was in no hurry to advance on Germany. Chief of Staff, Ludendorff, concentrated six divisions against Samsonov's left flank and withdrew the remaining troops in Gumbinnen to use against Samsonov's right flank. The German artillery forced a Russian retreat and continued to pursue them until they reached Neidenburg. A Russian counter - attack allowed two army corps units to escape before Germany surrounded the Russian centre. Germany took around 92,000 Russian prisoners and attacked Rennekamfp's army. The Russians were driven out of East Prussia with around 250,000 men killed and large amounts of military equipment were lost. It was a crushing defeat to the Russians.
"I beg most humbly to report to Your Majesty that the ring round the larger part of the Russian Army was closed yesterday. The 13th. 15th and 18th Army Corps have been destroyed. We have already taken more than 60,000 prisoners, among them the Corps Commanders of the 13th and 15th Corps. The guns are still in the forests and are now being brought in. The booty is immense though it cannot yet be assessed in detail. The Corps outside our ring, the 1st and 6th, have also suffered severely and are now retreating in hot haste through Mlawa and Myszaniec." - Message written by General von Hindenburg to the Emperor and King
Trueman, C. (2000). The Battle of Tannenberg. Retrieved February 23, 2015, from http://www.historylearningsite.co.uk/battle_of_tannenberg.htm