The ŁódźBattle of Łódź took place from 11 November to 6 December 1914, near the city of Łódź in Poland. It was fought between the German Ninth Army and the Russian First, Second, and Fifth Armies, in harsh winter conditions. The Germans redeployed their Ninth Army around Thorn, so as to threaten the Russian northern flank, following German reversals after the Battle of the Vistula River. The German objective was to prevent an invasion of Germany, and thus considered a success, though narrowly avoiding disaster.
Background
Grand Duke Nicholas Nikolayevich favored Nikolai Ruzsky's plan to invade Silesia on 14 November, with the Russian Second, Fifth, and Fourth Armies. The Russian Tenth and First Armies maintained pressure on East Prussia, while the Eighth Army pressed against the Carpathian passes, the Eleventh besieged Przemyśl, and the Third army advanced on Kraków. Hindenburg and Ludendorff had moved the German Ninth Army to the Thorn area, in an attempt to defend Silesia. The Ninth Army consisted of the XI, XVII, and XX Corps, plus the 3rd Guards Infantry Division, and the I Reserve and XXV Reserve Corps from the Eighth Army. Four divisions of the Austro-Hungarian Second Army took over the German Ninth Army's former positions, the remainder of Second Army troops then came under the command of the Austro-Hungarian Third army. The Germans had placed 15 infantry divisions, and 5 cavalry divisions, under Mackensen's Ninth Army in its drive on Łódź. However, the German advance faced 24 Russian infantry divisions and 8 cavalry divisions. The Scheidemann's Russian Second army was deployed around Łódź, with his IV, I and XXIII Corps on the Warta, and his II Corps at Łęczyca. Rennenkampf's Russian First Army was deployed further east, along the Vistula.
On 1 November, Paul von Hindenburg was appointed commander of the two German armies on the Eastern Front. His Eighth Army was defending East Prussia. Knowing Silesia would be invaded on 14 November, Hindenburg and Ludendorff decided not to meet the attack head-on, but to seize the initiative by shifting their Ninth Army north by railway to the border south of the German fortress at Thorn, where they were reinforced with two corps transferred from Eighth Army. The enlarged Ninth Army would then attack the Russian right flank, cutting Łódź off from Warsaw, and eliminating any troops thus encircled. In ten days Ninth Army was moved north by running 80 trains every day.
Battle
On 11 November, Mackensen's German Ninth Army I and XXV Reserve Corps struck at the V Siberia Corps of Rennenkampf's First Army, located near Włocławek on the left bank of the Vistula, before they could prepare defensive positions. The German XX Corps advanced on Lubraniec so as to attack the V Siberian Corps flank. Rennenkampf was refused permission to send his VI Siberian Corps from Wyszogród to the aid of the V Siberian Corps, who had to retreat. On 12 November, a gap formed between the Russian II and V Siberian Corps, as the V Siberian Corps was forced to retreat to the southeast, which Mackensen took advantage of on 13 November. On 14 November, Mackensen ordered his entire German Ninth Army to advance, with his XI Corps attacking the Russian XXIII Corps northern flank, his XVII and XX Corps engaging the Russian II Corps, and his I Reserve Corps was to capture Łowicz, while containing the VI Siberian Corps. Yet, the Russians were still unaware of the German force attacking them, as they started their invasion of Silesia. On 15 November, the Germans captured Kutno, and on 16 November, crossed the Bzura, while Scheidemann ordered his Russian I and IV Corps to retreat towards Łódź. As the German XX Corps captured Stryków, the XXV Reserve Corps captured Brzeziny on 18 November, while XX and XVII engaged the defenses of Łódź. The Russian Fifth Army's XIX and V Corps were ordered north to Skierniewice, in support of Second Army's left flank. It was Plehve's Russian Fifth Army which prevented German encirclement of Łódź from the south. In the interim, Rennenkampf's Russian First Army remained stationary, content to guard the approach to Warsaw.
Grand Duke Nicholas's primary objective was saving Second Army and avoiding a repeat of the disaster at Tannenberg. On 16 November he ordered Wenzel von Plehve's Russian Fifth Army to abandon the proposed offensive into Silesia and to move northward towards Łódź; they marched in only two days. As soon as Hindenburg saw the transcript of this order, he knew that his maneuver had succeeded. Now seven Russian corps were defending the city. Plehve smashed into Mackensen's right flank on 18 November in bitter winter conditions (at times the temperature dropped as low as .