Battle of Tannenberg
The annihilation of a Russian army in East Prussia in August 1914, which saved Germany's east, made Hindenburg, and set Russia on the road to 1917.
In five days at the end of August 1914, a German army destroyed a Russian one in East Prussia so completely that its commander shot himself in a forest rather than report the result. Tannenberg was the most one-sided victory of the First World War's opening campaign, and its consequences ran far past the battlefield: it created the political careers that would dominate Germany for two decades, and it began the sequence of military humiliation that ended with the Romanovs in a cellar.
Why Russia was there
Germany's war plan assumed Russia would take six weeks to mobilize, which is why almost the entire German army went west to knock France out first. Russia, pressed by France to relieve the pressure, mobilized far faster than expected and pushed two armies into East Prussia within weeks: the First under Rennenkampf from the northeast, the Second under Samsonov from the south.
The two Russian armies were separated by the Masurian Lakes, a barrier that forced them apart and made mutual support slow. Rennenkampf and Samsonov also disliked each other, an animosity that has been dramatized more than the evidence supports but that certainly did not help. Most importantly, Russian units transmitted orders by radio in the clear, without encryption, because their cipher arrangements had broken down. The Germans simply listened.
The initial German commander lost his nerve and proposed abandoning East Prussia. He was replaced by a retired general recalled from civilian life, Paul von Hindenburg, with Erich Ludendorff as his chief of staff. The plan they executed was largely the work of Colonel Max Hoffmann, who had drafted it before they arrived and who knew from intercepts exactly where Samsonov was going.
The encirclement
The Germans took an enormous risk. Knowing from radio intercepts that Rennenkampf's army in the north was advancing slowly and would not intervene, they left a thin screen in front of it and moved almost their entire force south by rail against Samsonov, using East Prussia's dense railway network to shift troops faster than the Russians could march.
Samsonov, believing he was pursuing a beaten enemy, pushed his center forward into a gap. German forces closed on both flanks. By 29 August the Russian Second Army was surrounded in the forests and lakes around Allenstein, and the pocket collapsed. Around ninety thousand Russian soldiers were taken prisoner and tens of thousands were killed or wounded. Samsonov walked into the woods on the night of 29 August and shot himself. German casualties were a small fraction of the Russian total.
The name is a piece of deliberate mythmaking. The fighting was not centered on the village of Tannenberg, but Hindenburg's staff chose it because in 1410 at that spot a Polish-Lithuanian army had destroyed the Teutonic Knights. Calling the battle Tannenberg framed it as a revenge five hundred years in the making, German civilization against the Slavic east. That framing was picked up enthusiastically, and it never went away.
What it produced
Strategically, Tannenberg did less than its fame suggests. The Russians came back, and the eastern front remained enormous and mobile for three more years. What it produced was people and myths.
Hindenburg became a national idol on the strength of a plan he did not write, and he and Ludendorff spent the rest of the war accumulating power until by 1916 they were running Germany as a de facto military dictatorship. Hindenburg was elected president of the Weimar Republic in 1925 and appointed Hitler chancellor in January 1933. The road from that forest in East Prussia to the Reichstag runs straighter than it should.
For Russia the consequences were structural. Tannenberg was the first of a series of defeats that discredited the tsarist command, and when Nicholas II took personal command of the army in 1915 he attached his own legitimacy to every subsequent failure. The army that broke in 1917 had been breaking since 1914.
And the German myth outlived the German victory. A colossal memorial was raised at the site in the 1920s, Hindenburg was buried there, and the Nazis staged rallies at it. In 1945 the retreating Wehrmacht demolished it and removed his remains rather than let the Red Army take them. The site is in Poland now, and there is nothing there.