East Prussia in the First World War

East Prussia, the easternmost province of the German Empire, was, besides Alsace-Lorraine, the only part of the Reich on whose soil this war was fought. In August 1914 two Russian armies invaded it and occupied about two-thirds of the province. At Tannenberg and the Masurian Lakes the Germans won their most famous victories in the east, but the Russians came back in the autumn and were finally driven out only in February 1915. For the inhabitants this meant two waves of flight, deportations and destroyed towns.

The Russian invasion (August 1914)

Russia had promised France to strike at Germany as soon as possible, and it marched on East Prussia before it had finished mobilising. From the east came the 1st Army of Paul von Rennenkampf; from the south, out of Congress Poland, came the 2nd Army of Alexander Samsonov. A single German army, the 8th, defended the province. On 17 August at Stallupönen General Hermann von François attacked the Russians against orders, and on 20 August the first great battle of the Eastern Front was fought at Gumbinnen, ending in a German defeat. The commander of the 8th Army, Maximilian von Prittwitz, then wanted to give up the whole province and fall back behind the Vistula, and was dismissed for it.

Tannenberg and the Masurian Lakes (1914)

The new commanders, Paul von Hindenburg and Erich Ludendorff, left only a screen against Rennenkampf and threw almost the whole army against Samsonov. In the Battle of Tannenberg, on 26–30 August, they encircled the 2nd Army in the forests between Hohenstein and Neidenburg. More than 90,000 Russians were taken prisoner, and Samsonov took his own life. In September the Germans turned on Rennenkampf and in the Battle of the Masurian Lakes drove him back across the border. The Russian offensive ended in disaster, but it forced the Germans to move two corps from the Western Front to the east on the eve of the Battle of the Marne.

The victories did not last long. After the failed German advance across the Niemen the Russian 10th Army entered East Prussia again in the autumn and occupied its eastern edge, with Lyck and Goldap. The front settled on the line of the Masurian Lakes and the Angerapp river.

The Winter Battle and the end of the fighting (1915)

In February 1915 two German armies struck both flanks of the Russian 10th Army in the snow. The Winter Battle in Masuria drove the last Russian troops out of the province, and XX Corps surrendered in the Augustów Forest. In March the Russians made one more raid from Courland into Memel, but after less than three days they were driven out. In the summer of 1915 the advance to the Narew and the Biebrza set off from East Prussia, and the front moved far to the east. The province became the hinterland of the front and saw no more fighting on its soil.

Refugees, deportations and rebuilding

Every Russian invasion set off a flight of the population. According to contemporary estimates about 870,000 people fled deeper into Germany in August 1914 and about 300,000 in October, while the whole province, according to the 1910 census, had just over two million inhabitants. The Russians suspected civilians of espionage and deported them into the interior of the empire, as far as Siberia. Up to 13,600 people were taken away, during the second occupation also women, children and the elderly. Many died, and only about 8,300 returned home after the war.

As early as 27 August 1914 Wilhelm II issued a decree on aid for East Prussia, and the state promised compensation. Talk of rebuilding the destroyed towns and villages began in 1914, after Tannenberg. According to the architectural historian Jan Salm, the rebuilding was meant not only to put a roof over people’s heads but also to serve German propaganda while the war was still being fought.

After the war the Treaty of Versailles cut the province off from the rest of Germany with land awarded to Poland, which German propaganda called the “corridor”. In the south of East Prussia the treaty ordered a plebiscite, which on 11 July 1920 ended in defeat for Poland: the vast majority of voters chose East Prussia.