Hindenburg takes command in the east

On 18 September 1914 General Paul von Hindenburg took command of the newly forming German Ninth Army. The British chronology of the war describes this as his appointment as commander-in-chief of the German armies in the east. Formally, Hindenburg received that title, as Oberbefehlshaber Ost, only on 1 November. In September he commanded the Ninth Army, while the existing Eighth Army in East Prussia was taken over by General Richard von Schubert. According to some accounts, however, Hindenburg retained authority over both armies, and in practice it was he and his chief of staff Erich Ludendorff who decided German operations in the east.

An ally in trouble

In mid-September 1914 the situation on the Eastern Front was mixed for the Central Powers. In East Prussia the Germans had won two great victories: at Tannenberg and at the Masurian Lakes. In the south, however, the Austro-Hungarian army had lost the Battle of Galicia. The Russians had taken Lviv, and the Austro-Hungarian forces were falling back behind the San and towards Kraków. The Chief of the Austro-Hungarian General Staff, Franz Conrad von Hötzendorf, was pressing the Germans to come to his aid.

The new Chief of the German General Staff, Erich von Falkenhayn, agreed to form a new army on the Silesian border. Its core consisted of corps brought by rail from the Eighth Army, reinforced by units from other sectors and by reserves. The Ninth Army headquarters was set up on 19 September in Breslau, and the troops concentrated in Upper Silesia and east of Częstochowa, next to the left wing of the Austro-Hungarian army. Command was entrusted to the victor of Tannenberg, with Ludendorff remaining his chief of staff.

The offensive on Warsaw

For the Polish lands the decision of 18 September had direct consequences. On 28 September the Ninth Army began its advance through the Kingdom of Poland towards the Vistula, in cooperation with the Austro-Hungarians, who attacked in Galicia at the same time. At the beginning of October the Germans reached the Vistula, and their units under General August von Mackensen came within a dozen or so kilometres of Warsaw. In the Battle of Warsaw and Ivangorod, that is, Dęblin, the Russians nevertheless gathered superior forces and from mid-October went over to counter-attacks. At the end of October Hindenburg withdrew the Ninth Army to the west. As he went, he destroyed roads, bridges and railway lines behind him to delay the Russian pursuit.

Ober Ost

On 1 November 1914 Hindenburg became commander-in-chief of all German forces on the Eastern Front, Oberbefehlshaber Ost, Ober Ost for short. Mackensen took over the Ninth Army, whose troops were moved by rail to the area of Thorn, from where in November they struck the Russians in the flank, leading to the Battle of Łódź. On 27 November Hindenburg was promoted to field marshal. His partnership with Ludendorff directed operations on the Eastern Front until August 1916, when the two of them took over the supreme command of the whole German army.