Main battles, fights, military operations
The Vilna operation of 1915, a defensive action of the 10th and 5th armies of the Russian Western Front held on 9 (22) August – 19 September (2 October) near Vilna (Vilnius).
Having taken on August 9 (22) the fortresses of Kovno (Kaunas), the 10th German army (commander General Eichhorn) advanced between the rivers Vilija and Neman trying to bypass Vilna from the north and to surround the main forces of the 10th Russian army (commander General N.A. Radkevich) concentrated in the northwest of Vilna. The impact of German armies forced the Russian command to strengthen this site of front with three corps. Having kept the Vilna district, Russian armies in the encounter attacks which lasted till the beginning of September caused big losses to the enemy. As German armies could not break through Russian defense, the German command, having strengthened the 10th army with reserves, started on 27 August (8 September) the attack on Sventsyany, the meeting-point of the 5th (commander General V.К. Pleve) and the 10th armies. These actions had got the name of the Sventsyany breakthrough. From the north and the south, the 10th German army was supported by the Neman army and the 8th army.
On 28 August (9 September) German armies managed to break through Russian defense to the north of Vilkomir. Six cavalry divisions engaged to the breakthrough had rejected a not numerous Russian cavalry and rushed to the Vilejka district, Molodechno.
On 1(14) September, German troops took Vilejka and approached Molodechno while their advanced detachments reached a railway in the east of Minsk. However by this time the impact of German cavalry, deprived of the support of infantry and artillery, had weakened, and on 2–3 (15–16) September it was stopped by detachments of the newly raised 2nd Russian army.
In the further the Russian army’s counterstroke overthrew the enemy forces, crushed German cavalry and rejected it from the Molodechno district to the lake Naroch. By 19 September (2 October) the Sventsyany breakthrough had been localized by Russian troops on the line of the lake Drisvjaty, the lake Naroch and Smorgon.