On the Eastern Front under the command of General Paul von Hindenburg, Ludendorff was instrumental in inflicting a series of crushing defeats against the Russians, including at Tannenberg and the Masurian Lakes.

After the war, Ludendorff became a prominent nationalist leader and a promoter of the stab-in-the-back myth, which posited that Germany's defeat and the settlement reached at Versailles were the result of a treasonous conspiracy by Marxists, Freemasons and Jews.

Through Dziembowski's wife Johanna Wilhelmine von Unruh (1793–1862), Erich was a remote descendant of the Counts of Dönhoff, the Dukes of Liegnitz and Brieg and the Margraves and Electors of Brandenburg.

The famous World War II General Heinz Guderian attended the same Cadet School, which produced many well-trained German officers.

"[9] Barbara Tuchman characterizes Ludendorff in her book The Guns of August as Schlieffen's devoted disciple who was a glutton for work and a man of granite character but who was deliberately friendless and forbidding and therefore remained little known or liked.

At the outbreak of war in the summer of 1914 Ludendorff was appointed Deputy Chief of Staff to the German Second Army under General Karl von Bülow.

As the victor of Liège, Ludendorff was awarded Germany's highest military decoration for gallantry, the Pour le Mérite, presented by Kaiser Wilhelm II himself on 22 August.

Early in 1915 Hindenburg and Ludendorff surprised the Russian army that still held a toehold in East Prussia by attacking in a snowstorm and surrounding it in the Second Battle of the Masurian Lakes.

Erich von Falkenhayn, supreme commander at the OHL, came east to attack the flank of the Russian army that was pushing through the Carpathian passes towards Hungary.

Outgunned, during the summer of 1915 the Russian commander Grand Duke Nicholas shortened his lines by withdrawing from most of Poland, destroying railroads, bridges, and many buildings while driving 743,000 Poles, 350,000 Jews, 300,000 Lithuanians and 250,000 Latvians into Russia.

Far-reaching plans envisioned Courland and Lithuania turned into border states ruled by German military governors answerable only to the Kaiser.

[14] He proposed massive annexations and colonization in Eastern Europe in the event of the victory of the German Reich, and was one of the main supporters of the Polish Border Strip.

[17] As to the various nations and ethnic groups in conquered territories, Ludendorff believed they were "incapable of producing real culture"[18] On 16 March 1916, the Russians, now with adequate supplies of cannons and shells, attacked parts of the new German defenses, intending to penetrate at two points and then to pocket the defenders.

Following the overthrow of Tsar Nicholas II of Russia, the new Russian government launched the Kerensky Offensive in July 1917, attacking the Austro-Hungarian lines in Galicia.

The Germans capped the year in the East by capturing the strong Russian fortress of Riga in September 1917, starting with a brief, overwhelming artillery barrage using many gas shells then followed by infiltrating infantry.

Ludendorff insisted on the huge territorial losses forced on Russia in the Treaty of Brest-Litovsk, even though this required that a million German soldiers remain in the east.

Ludendorff regarded the Germans as the "master race"[43] and after victory planned to settle ex-soldiers in the Baltic states and in Alsace-Lorraine, where they would take over property seized from Balts and the French.

They issued a directive on elastic defense, in which attackers who penetrated a lightly held front line entered a battle zone in which they were punished by artillery and counterattacks.

[45] By February 1917 the OHL was sure that the new French commander, General Robert Nivelle, would attack, and correctly foresaw that he would try to pinch off the German salient between Arras and Noyon.

So the OHL withdrew German forces to the segment of the Hindenburg line across the base of the salient in Operation Alberich, leaving the ground they gave up as a depopulated waste land.

The Allies were aghast, but it was not the triumph OHL had hoped for: they had planned another Tannenberg by surrounding tens of thousands of British troops in the Cambrai salient,[49] but had been thwarted by stout defense and fighting withdrawal.

Again they broke through, advancing 30 km (19 mi), and forcing the British to give back all of the ground that they had won the preceding year after weeks of battle.

[citation needed] Then the Germans struck near Reims, to seize additional railway lines for use in the salient, but were foiled by brilliant French elastic tactics.

A telephone call reported that the French and Americans, led by a mass of tanks, had smashed through the right flank of their salient pointing toward Paris, on the opening day of the Battle of Soissons.

OHL still vigorously opposed offering to give up the territory they desired in France and Belgium, so the German government was unable to make a plausible peace proposal.

[citation needed] The influential military analyst Hans Delbrück concluded that "The Empire was built by Moltke and Bismarck, destroyed by Tirpitz and Ludendorff.

Ludendorff was convinced that Germany had fought a defensive war and, in his opinion, that Kaiser Wilhelm II had failed to organize a proper counter-propaganda campaign or provide efficient leadership.

Ludendorff claimed that he paid close attention to the business element (especially the Jews), and saw them turn their backs on the war effort by—as he saw it—letting profit, rather than patriotism, dictate production and financing.

In 1925, he founded the Tannenbergbund, a German nationalist organization which was both anti-Semitic and anti-Catholic, and published literature espousing conspiracy theories involving Jews, Catholics—especially Jesuits—and Freemasons.

Ludendorff felt so humiliated by what he saw as a betrayal by his old friend that he broke off relations with Hindenburg, and in 1927 refused to even stand beside the field marshal at the dedication of the Tannenberg memorial.