The Battle of Tannenberg was fought between the Russian Empire and the German Empire at the beginning of the First World War.
The battle saw Russian troops advance into German territory, as Russia began the mass mobilisation of its forces.
The Russian advance was halted by German forces, who extracted heavy losses on the Russian First, and particularly Second Army.
The battle ended with a Russian retreat.
No Russian offensive would be fought on German soil for the remainder of the war.
Although the battle did not actually take place at Tannenberg, it was chosen as to restore pride to the name after the defeat of the Teutonic Knights at the Battle of Tannenberg in 1410.
Posted by: Daniel Barry, Centenary News