With the outbreak of World War I, Breslau's VI. Army Corps was sent to the western front to form the pivot of the Schlieffen plan, while the 1st "Leibkürassiere" saw action at the battle of the Marne before they were moved to the Eastern Front. The end of Germany's western offensive and the absence of the VI. Army Corps left Silesia and Breslau dangerously exposed. In 1914/15 the Russian army stopped only 80 km to the east of Breslau, which led to the evacuation of children and the erection of barbed-wire defenses. The Silesian Landwehr under General Remus von Woyrsch was rapidly deployed to face the Russian army, but German victories at the Masurian lakes and Gorlice soon eliminated this threat.