Battle of Tannenberg, 1914: Germany destroys a Russian army

In the last days of August 1914, in the lakes and forests of East Prussia, the German Eighth Army surrounded and destroyed an entire Russian field army. Its commander walked into the forest and shot himself. Britannica calls the victory a singular achievement, unique in its scale in the whole war; Oxana Nagornaja, writing for the International Encyclopedia of the First World War, stresses that its weight was less strategic than symbolic, and that it became one of the founding myths of interwar Germany.²

Background: two Russian armies invade East Prussia

Germany went to war in 1914 with the Schlieffen Plan, which sent nearly all its strength against France and left a single army, the Eighth, to hold East Prussia. The German staff expected Russia's vast distances to slow its mobilization for weeks. Instead, pressed by France to attack early, Russia sent two armies over the frontier long before they were fully ready.³

The plan, Britannica explains, was a pincer. General Paul von Rennenkampf's First Army would advance from the east and draw the Germans onto itself; two days later General Alexander Samsonov's Second Army would cross the southern frontier and cut the Germans off from the Vistula. Between the two armies lay the long chain of the Masurian Lakes, and over both stood General Yakov Zhilinsky, commander of the Northwestern Front.⁴

Rennenkampf crossed the frontier on 17 August and on 20 August threw back the Eighth Army at Gumbinnen. Its commander, General Max von Prittwitz, lost his nerve at the news that Samsonov was coming up from the south and announced that he would retreat behind the Vistula, giving up East Prussia. His staff officers, Lieutenant Colonel Max Hoffmann among them, argued against it, and Prittwitz soon dropped the idea, but he had already told the Supreme Command, and he was replaced.⁵

Armies and commanders

The new commander was Paul von Hindenburg, a general who had retired in 1911 and was called back to service at 66. His chief of staff was Erich Ludendorff. The two men reached the Eighth Army on 23 August. Ludendorff found the troop movements Hoffmann had already set going fitted his own ideas, and confirmed them.⁶

On the Russian side Samsonov, like Rennenkampf, was a cavalryman who had fought against Turkey and Japan. His army had five corps, with ten infantry and three cavalry divisions, but Zhilinsky had driven it forward so hard through a desolate, roadless border region that, in Britannica's words, its troops were tired and hungry, its transport incomplete and its supply services in chaos.⁷

How the two sides compared is disputed. Nagornaja writes that the Germans surrounded divisions that outnumbered them, and Britannica calls the force first gathered against Samsonov's left inferior in strength to the Russians. Ironside, counting every unit that took part, gives the Germans 155 infantry battalions against 132 Russian, and a ten-to-one superiority in heavy guns: 128 against 12. Across East Prussia as a whole, Britannica notes, the two Russian armies together had more than a two-to-one superiority; the German achievement was to bring nearly all their strength against one of them.⁸

What the Germans had was information. The Russians sent their orders by wireless either in clear or in a cipher simple enough to read with ease, and the intercepts showed both that Rennenkampf was in no hurry to come south and where Samsonov's corps would be. Edmund Ironside, the British officer who wrote one of the first detailed studies of the campaign in 1925, put the apparent precision of the German movements down to exactly this rash use of wireless.⁹

The battle in phases

The trap is set, 23 to 26 August

The plan rested on the railways. While a thin cavalry screen faced Rennenkampf, divisions were taken back from the Gumbinnen front by train to join Friedrich von Scholtz's XX Corps in the south, facing Samsonov's center. Then, as the intercepts showed Rennenkampf still idle, Ludendorff took the bigger risk of marching August von Mackensen's XVII Corps and the I Reserve Corps south as well, to strike Samsonov's other flank. Meanwhile Samsonov's corps were spread over a wide front, their flanks far apart, leaving the Germans ever more room between the two Russian armies.¹⁰

On 26 August the battle opened along the whole front. In the east, Mackensen's and the reserve corps fell on the Russian VI Corps, the right wing of the Second Army, and forced it back toward the frontier. In the west, Ludendorff wanted Hermann von François to attack the Russian left with his I Corps at once; François insisted on waiting for his heavy artillery to arrive.¹¹

The breakthrough at Usdau, 27 August

Britannica places the real crisis of the battle on 27 August. That morning François, now well supplied with shells, opened a fierce bombardment on the Russian I Corps near Usdau, and the Russians broke and fled before the German infantry reached them. The Polish historical portal dzieje.pl goes as far as to say that without his insubordination the Germans would probably not have broken the Russian defense. Samsonov moved his own headquarters up to Neidenburg that day and met the routed troops streaming into the town.¹²

The ring closes, 28 to 30 August

François, disobeying orders again, turned east toward Neidenburg and the road to Willenberg, across the rear of the Russian center. By the night of 29 August his troops held that road with a chain of posts. The Russian XIII and XV Corps, falling back, found the roads blocked and broke up in the forests into what Britannica calls a mob of hungry and exhausted men. They surrendered in tens of thousands. A belated attempt by Rennenkampf's army to come to the rescue was too late and was held off.¹³

Turning point: Samsonov in the forest

Samsonov had ridden forward to take control of the battle and was caught up in the retreat. On the night of 29 to 30 August he and a few officers tried to walk out through the forest. Ironside tells how, exhausted and with a weak heart, the general slipped away from his staff in the darkness; they heard a single revolver shot. He had taken his own life rather than survive the disaster, and his body was later found by German troops.¹⁴

By 31 August the Second Army was finished. Its XIII and XV Corps had been annihilated, and the rest badly shaken; according to Ironside only about 50 officers and 2,000 men of those two corps escaped.¹⁵

Aftermath

The figures vary by source. Britannica counts 30,000 Russians killed or wounded and some 92,000 taken prisoner, against 13,000 German casualties, and about 400 guns lost. Nagornaja puts the Russian loss at about 120,000 men, 95,000 of them prisoners. The German claim, as Ironside reports it, was 95,000 unwounded and 30,000 wounded prisoners and 500 guns. The Deutsches Historisches Museum speaks of 140,000 Russians killed or wounded. All agree that the Second Army had ceased to exist as a fighting force.¹⁶

With two fresh corps from the Western Front, the Eighth Army then turned on Rennenkampf and drove him out of East Prussia in the First Battle of the Masurian Lakes in September. In these East Prussian battles, Britannica reckons, Russia lost some 250,000 men. Yet the victory did not decide the war in the east: Nagornaja notes a second, brief Russian incursion that winter, and dzieje.pl that the threat to East Prussia was lifted only in 1915.¹⁷

Whether Tannenberg changed the war in the west is still argued. Moltke sent two corps from the Western Front to the east, and they arrived too late to fight at Tannenberg. Britannica and dzieje.pl hold that their absence helped make possible the French recovery on the Marne. Ironside doubted it: Moltke had fifteen days before the Marne to fill the gap from his left wing, he argued, and chose not to.¹⁸ › The First Marne, 1914

Legacy and memory

The battle was not fought at Tannenberg. Most of it raged around Hohenstein and Allenstein, and Nagornaja calls it the Battle of Allenstein before it received its famous name. The Germans chose Tannenberg on purpose: it was the German name of Stębark, near Grunwald, where the Polish and Lithuanian army had defeated the Teutonic Knights in 1410. German propaganda presented the victory as revenge for that defeat, a new round in an age-old struggle between Germans and Slavs.¹⁹ › Battle of Grunwald, 1410

The victory made Hindenburg a national idol. Britannica notes that the nation applauded the rocklike Hindenburg rather than Ludendorff, and that his standing soon overshadowed the emperor's. Britannica's own verdict is that the chief credit for the design belongs to Hoffmann and the most essential share in the execution to François. The Deutsches Historisches Museum describes Tannenberg as the seed of a Hindenburg cult that outlived the war and fed the nationalist right against the Weimar Republic; in 1925 Hindenburg was elected its president.²⁰

In 1927 a monumental memorial was completed near Hohenstein. When Hindenburg died in 1934 his funeral was held in its courtyard, and in 1935, when he was laid to rest there, the Nazis declared it a national memorial. Its end is told two ways: dzieje.pl says the Germans blew it up in January 1945 so that it would not fall to the Soviets, after removing Hindenburg's remains, while the Deutsches Historisches Museum attributes the demolition to Russian troops.²¹

For Russia the defeat cast a long shadow. Nagornaja describes the shock to morale, the inquiry that assessed the causes soberly, and the legends that grew in its place: that Russia had sacrificed an army to save Paris, and that Rennenkampf had betrayed Samsonov. Polish historians, in the words of dzieje.pl, share the blame among Rennenkampf, Samsonov and Zhilinsky, who attacked Rennenkampf hardest to hide his own failures.²²

The war in the east went on at Łódź before the year was out. See what else happened on 26 August, the day Tannenberg began, or test yourself in the World War I battles quiz.