Fighting on the Niemen begins

On 25 September 1914, according to the British chronology of the war, fighting began on the Niemen. The German 8th Army, which in mid-September had driven the Russians out of East Prussia, crossed the Russian border and came up against the Russian positions on the river. It tried to seize the crossings between Grodno and Kovno. According to various accounts, the fighting covered the sector from Olita to Druskieniki and the area of Sopoćkinie. The fighting took place on lands of the former Polish-Lithuanian Commonwealth, largely in the Suwałki region and its neighbourhood.

After the Battle of the Masurian Lakes

After the end of the Battle of the Masurian Lakes the Russian 1st Army of General Paul von Rennenkampf withdrew behind the Niemen. The Germans followed it and occupied part of the border lands of the Kingdom of Poland, including Suwałki and Augustów. In mid-September, however, Hindenburg and Ludendorff left for Silesia to form a new 9th Army there and help the Austrians, who had been beaten in Galicia. Some of the troops from East Prussia went with them. Command of the weakened 8th Army was taken over by General Richard von Schubert.

The Germans wanted to exploit the advantage their victory had given them and to prevent a new Russian offensive against East Prussia. The attack on the Niemen was also meant to tie down Russian forces while a thrust towards Warsaw and Dęblin was being prepared in the south.

On the river

The Russians, however, had had time to prepare. The 1st Army dug in behind the Niemen, and between Grodno and Augustów the new 10th Army of General Vasily Flug was assembling, made up among others of Caucasian, Siberian and Turkestan corps brought from distant districts of the empire. Both armies were subordinate to the North-Western Front, now commanded by General Nikolai Ruzsky. The Russians had a clear numerical superiority, and the Niemen, with its fortresses at Grodno and Kovno, formed a strong line of defence.

The German attack made heavy going from the start. The details of this fighting are poorly documented, and Russian and German studies present it differently. According to Russian accounts, German attempts to cross, among others near Druskieniki, broke down under the fire of the defenders dug in on the far bank. Nowhere did the Germans manage to gain a lasting bridgehead across the Niemen. Meanwhile on the left bank of the river, in the forests west of Grodno, heavy clashes took place with units of the 10th Army.

The Russian counter-attack

After a few days the initiative passed to the Russians. At the end of September the 10th Army went over to the attack in the Augustów Forest, where in the wooded terrain the Germans could not exploit their superiority in heavy artillery. The Germans had to break off their offensive on the Niemen and fall back towards the border. At the beginning of October the Russians recovered Augustów and Suwałki, and then once again entered the eastern fringes of East Prussia.