The Battle of Gumbinnen, initiated by forces of the German Empire on 20 August 1914, was a German offensive on the Eastern Front during the First World War. Because of the hastiness of the German attack, the Russian Army emerged victorious. Background According to Prit Buttar, "Provided that the Russians did not concentrate all their forces against East Prussia - and therefore sent substantial numbers of troops against the Austro-Hungarian Empire - Eighth Army should be able to hold out without conceding too much ground until victory over France was assured. All that was required was for Prittwitz to avoid defeat, and to hold his nerve. Originally, Prittwitz had intended to hold the line of the Angerapp and allow Rennenkampf to suffer heavy casualties while trying to force the position." The Eighth Army comprised four corps: I Corps (Hermann von François), XVII Corps (August von Mackensen), I Reserve Corps (Otto von Below), and XX Corps (Friedrich von Scholtz), plus 1st Cavalry Division, facing the Russian First Army (Paul von Rennenkampf) and Russian Second Army (Alexander Samsonov). The Russians enjoyed considerable numerical superiority, but were hampered by significant deficiencies in their services of supply and field communications. German aerial reconnaissance by the Flieger Abteilung 16 indicated a gap had formed between the Russian First and Second armies, while radio intercepts indicated Rennenkampf had halted his army for a rest on 20 August. François' scouts, following his success at the Battle of Stallupönen, reported the northern flank of the Russian First Army was exposed, and requested the 2nd Infantry Division for an attack, with support by the XVII Corps and I Reserve Corps. Reluctantly agreeing, Prittwitz commented, "I Corps had made a soup for us, and we will now have to eat it up." German attack and retreat With his initial success, François had persuaded Prittwitz to launch an offensive against the Russian First Army while the Second Army was still far to the south. François argued that his troops, many of whom were native East Prussians, would be demoralized by retreating and leaving their homeland to the Russians, and that the Russians were not as strong as they appeared to be. A radio message that did not use codes supported this assessment. On the morning of 20 August, after a night march, the German 2nd Infantry Division advanced through the Züllkinner Forest and outflanked the Russian 28th Infantry Division, having been