Russian invasion of East Prussia (1914)

August 17 – September 14, 1914 · East Prussia

Russian armies advanced into German East Prussia early in the war but were beaten at Tannenberg and the Masurian Lakes. The defeats ended the invasion and cost Russia heavily.

On the map Contemporaries

Central Powers

Allies

German Empire

Russian Empire

Paul von Hindenburg military commander

Erich Ludendorff military commander

Maximilian von Prittwitz military commander

Max Hoffmann military commander

Grand Duke Nicholas Nikolaevich of Russia military commander

Paul von Rennenkampf military commander

Alexander Samsonov military commander

Yakov Zhilinskiy military commander

Strength and losses

Strength: 256,388
Casualties: 37,000–100,000

Strength: 750,422
Casualties: 270,000–320,000
Captured: 100,000