Whence the Russian Army After Tannenberg?

Russian Prisoner Column, Post-Tannenberg

From David Stone's The Russian Army in the Great War, Univ. of Kansas Press, 2015

The sacrifices that Rennenkampf’s and Samsonov’s soldiers had made were not pointless. As they did not destroy the Eighth Army or occupy East Prussia, the Russian plan in that sense failed, but all the powers fell short in their initial hopes. As S. L. A. Marshall wrote, “All four of the Continental powers  suffered delusions; all tried at the same time to swing for a knockout blow; all four failed.” More importantly, the Russian invasion of East Prussia did make the German high command weaken its drive on Paris in order to shore up German defenses in the east. Russian troops on German soil had galvanized public opinion. Wilhelm Düwel, a Social Democrat and not inclined to take the kaiser’s word at face value, nonetheless warned of “semi-barbarians, who scorch, murder, loot, who shoot at Samaritans, who vandalize medical stations, and spare neither women not the injured.” Rumors of Russian atrocities drove refugees west toward safety and required immediate action.

Hans von Plessen, military aide to Kaiser Wilhelm, wrote in his diary “East Prussia . . . occupied by the enemy! The Russians burn and pillage everything!—We must make haste to finish up in the West as quickly as possible in order to come to the rescue of the East.”  The result was that two corps, the Guard Reserve and XI Corps with a cavalry division, went east on 26 August. Too late to have any effect on the invasion of East Prussia, they did weaken the German drive on Paris, a close-run affair where the presence or absence of two corps might have made a difference.

Russian Infantry Still Ready to March

Tannenberg was unquestionably a major defeat for the Russians, but its significance is easy to overstate. The cost to the Russian war effort was the devastation of the Second Army, the total destruction of two corps (XV and XIII) and partial destruction of another (XXIII) out of thirty-seven corps in the Russian order of battle, and the loss of 50–70,000 casualties and 92,000 prisoners of war. Foreign Minister Sazonov told an American correspondent that Russia had lost 165,000 men in three days.

Of Samsonov’s original corps, however, the I and VI remained largely intact in defensive positions along the Narew River, along with substantial remnants of the XXIII Corps; the II Corps was now part of Rennenkampf’s First Army. Thus half of the Second Army remained to screen the northern approaches to Warsaw against the very real chance that the Eighth Army might press south into Poland to relieve Germany’s hard-pressed Austrian allies. AustriaHungary begged Germany for such a step, hoping for a German attack on Warsaw or Siedlce. The German high command had no such intention, not while Rennenkampf’s First Army still remained on German soil. Evenwhile the remnants of Samsonov’s shattered divisions were being mopped up, the German high command ordered Hindenburg to clear East Prussia in preparation for a later offensive south into Poland.

While Rennenkampf’s First Army remained on German territory, the initial East Prussian campaign was not complete. Half of Samsonov’s army had been destroyed; his surviving corps had withdrawn back across the border to regroup. Rennenkampf, however, was still inching west into East Prussia, and now faced Hindenburg’s Eighth Army alone. At Zhilinskii’s urging, Rennenkampf had sent his cavalry ranging ahead toward the pocketed Samsonov. At the same time, Zhilinskii had sabotaged this rescue effort by instructing Rennenkampf to divert troops to screen Königsberg, whose garrison was utterly irrelevant to the campaign. In any event, the  cavalry sent to Samsonov’s relief were withdrawn by the end of August when Samsonov’s destruction became clear.  

This November 1914 French map shows Russian
 operations after Tannenberg.  Note the modest
advances in East Prussia; major advances
through Poland; and major advance through
Galicia, with a subsequent partial withdrawal; 
while holding A-H Fortress Przemyśl under siege.

The ongoing mobilization of reserves on both sides was already beginning to change the nature of the war, only weeks into the fighting. The initial battles in East Prussia had been fought by formations that had been forced to fight with open flanks, since the density of manpower and wide spaces of East European terrain meant that there were simply not enough units to maintain continuous fronts. The Russian mobilization system was beginning to tap into the country’s colossal human reserves. . . [The] key campaigns in late 1914 and 1915 were an enormous test for the Russian Empire, but also demonstrated that Russia’s resources of population and space made German victory difficult to achieve.