The Battle of Stalluponen, the first battle of the Eastern Front, was fought between the German 8th and the Russian General Rennenkampf's First Army. The Russians planned to invade East Prussia in the North and South. The North attack would be led by Rennenkampf's First Army and the South attack would be led by General Samsonov's Second Army. Rennenkampf 's army ran into a single Germany army corps, led by General Hermann von Francois, and was badly defeated, losing 3,000 men. Rennenkampf withdrew to the border and Francois withdrew to Gumbinnen.
General Herman von Francois General Paul von Rennenkampf