Battle on Eastern Front during First World War. The recently formed German Ninth Army, under General August von Mackensen, had been sent to aid the beleaguered Austrians against Russian attack and to prevent any Russian attack on Central Germany. Mackensen struck between the Russian First and Second armies, crushing the First, and coming close to surrounding the Second, before Russian counterattacks aided by a march of seventy miles in forty eight hours relieved them. While the battle was technically a Russian victory, the Germans achieved their aim, and the Russians withdrew, never again to come so close to German soil.