Question: Max Hoffmann along with Hindenburg and Ludendorff, masterminded the devastating defeat of the Russian armies in a battle fought when ?

<P0-S0> Carl Adolf Maximilian Hoffmann (25 January 1869 – 8 July 1927) was a German military strategist. <P0-S1>  As a staff officer at the beginning of World War I, he was Chief of Staff of the 8th Army. <P0-S2>  Hoffmann, along with Hindenburg and Ludendorff, masterminded the devastating defeat of the Russian armies at Tannenberg and the Masurian Lakes. <P0-S3>  He then held the position of Chief of Staff of the Eastern Front. <P0-S4>  At the end of 1917, he negotiated with Russia to sign the Treaty of Brest-Litovsk. <P0-S5>  In 1922, he tried to set up an anti-Soviet coalition without success. <SEP> <P1-S0> The Battle of Tannenberg was fought between Russia and Germany from 26–30 August 1914, during the first month of World War I. <P1-S1>  The battle resulted in the almost complete destruction of the Russian Second Army and the suicide of its commanding general, Alexander Samsonov. <P1-S2>  A series of follow-up battles (First Masurian Lakes) destroyed most of the First Army as well and kept the Russians off balance until the spring of 1915. <P1-S3>  The battle is particularly notable for fast rail movements by the Germans, enabling them to concentrate against each of the two Russian armies in turn, and also for the failure of the Russians to encode their radio messages. <P1-S4>  It brought considerable prestige to Field Marshal Paul von Hindenburg and his rising staff-officer Erich Ludendorff. <SEP> <P2-S0> Operation "Michael" was a major German military offensive during the First World War that began the Spring Offensive on 21 March 1918. <P2-S1>  It was launched from the Hindenburg Line, in the vicinity of Saint-Quentin, France. <P2-S2>  Its goal was to break through the Allied (Entente) lines and advance in a north-westerly direction to seize the Channel ports, which supplied the British Expeditionary Force (BEF) and to drive the BEF into the sea. <P2-S3>  Two days later General Ludendorff, the Chief of the German General Staff, changed his plan and pushed for an offensive due west, along the whole of the British front north of the River Somme. <P2-S4>  This was designed to separate the French and British Armies and crush the British forces by pushing them into the sea. <P2-S5>  The offensive ended at Villers-Bretonneux, to the east of the Allied communications centre at Amiens, where the Allies managed to halt the German advance; the German Armies had suffered many casualties and were unable to maintain supplies to the advancing troops. <SEP> <P3-S0> In 1918, the German Army in the east was the most powerful force in the region. <P3-S1>  Even more importantly, it was not only undefeated, it was victorious (in contrast to the German Army on the western front). <P3-S2>  However the commander of the German forces in the east, Max Hoffmann, a chief negotiator in the Treaty of Brest-Litovsk, was facing increasing difficulties. <P3-S3>  He believed, rightly, that his army was the only stabilising influence over the Eastern Europe. <P3-S4>  Yet with the disintegration of Austria-Hungary, rise of Bolsheviks in the east and various independent governments between the former frontline and Germany, the former "Oberkommando-Ostfront" (or "Ober-Ost") occupation zone became a thin line to nowhere, connected only to still-German Prussia. <P3-S5>  The deteriorating situation in Germany, facing the threat of civil war, eventually forced Hoffman to begin to retreat westwards, to Germany, in December 1918. <P3-S6>  Demoralized officers and mutinous soldiers abandoned their garrisons "en masse" and returned home. <P3-S7>  Only a limited number of units still retained any combat strength.