Battle of Vilnius (1915)

In late summer 1915, the Battle of Vilnius unfolded in the region between Vilnius, Grodno, and Daugavpils. It was a strategic withdrawal by Russian forces on World War I’s Eastern Front, following a successful German summer offensive. German troops were directly commanded by Otto von Below and Hermann von Eichhorn, while Field Marshal Paul von Hindenburg served as the overall army group commander. Though weakened by the transfer of twelve divisions to France and the Balkans, Hindenburg ordered several secondary offensives while taking up defensive positions. Half of the Russian forces and the main German forces on the Eastern Front took part in the battle. However, the German failure to achieve lasting success was primarily due to logistical overextension, Russian counterattacks, and the decision to halt, not solely Russian numerical superiority. Further German actions failed: they suffered losses and did not capture Daugavpils.

**Background** Hindenburg’s Army Group had limited success after the sieges of Kaunas and Novogeorgievsk. This forced General Erich von Falkenhayn, Chief of the German Great General Staff, to decide to wind down operations on the Eastern Front, especially since large troop movements were needed for the offensive against Serbia and for strengthening defenses in France and Belgium. On August 27–28, 1915, Emperor Wilhelm II, at Falkenhayn’s urging, issued a directive for the urgent construction of long-term defensive zones on the Eastern Front, from the Baltic Sea north of Mitava to the Narew River and on to Kovel. At the same time, the army groups of Prince Leopold of Bavaria and August von Mackensen were to continue their offensive only to seize positions more convenient for defense (bypassing Białowieża Forest from the north), while Hindenburg’s group was to “cause a major defeat to the enemy.”

Major changes occurred in the management of the Russian field army. On August 17, Chief of Staff of the Supreme Commander Nikolai Yanushkevich ordered the division of the Northwestern Front’s armies, despite objections from Commander-in-Chief Mikhail Alekseyev. On the night of August 31, the Northern Front’s directorates were formed; General of Infantry Nikolai Ruzsky was appointed commander-in-chief, with Major General M. Bonch-Bruyevich as his chief of staff. The front included the 6th, 5th, and 12th Armies—the latter’s command was trans