Battles - The Battle of Stalluponen, 1914
The first action on the Eastern Front, the Battle of Stalluponen (in present day Lithuania) was fought by a corps of the German Eighth Army against Russian General Rennenkampf's First Army.
Russia's planned invasion of East Prussia - which comprised a major component of their pre-war strategy, Plan 19 - was two-pronged. Rennenkampf's First Army, of 200,000 men, entered East Prussia from the north while General Samsonov's Second Army invaded from the south.
Rennenkampf's forces marched into East Prussia on 17 August 1914, following cavalry probes conducted five days earlier, the same day that General Hermann von Francois, commander of I Corps - attached to General von Prittwitz's Eighth Army - brought them to action.
Launching a frontal attack, the aggressive Francois drove the Russians back to the frontier, snapping up 3,000 prisoners in the process. Prittwitz, who had no prior knowledge of Francois's unauthorised attack, believed his strategy to be dangerous in the extreme, fearing that Francois's forces could feasibly be encircled by Rennenkampf's much larger force. He consequently ordered Francois to call off his offensive before the latter could exploit his unexpected victory.
As Francois's corps withdrew to Gumbinnen, Rennenkampf's army resumed its slow march westward into East Prussia. Francois urged Prittwitz to launch an offensive against Rennenkampf sooner rather than later. Prittwitz, encouraged by Francois's initial success, concurred, authorising a much larger attack upon the Russian First Army three days later, on 20 August, at the Battle of Gumbinnen.