Battle of Warsaw (1920)
The battle of Warsaw was fought from August 12–25, 1920 as Red Army forces commanded by Mikhail Tukhachevsky approached the Polish capital of Warsaw and the nearby Modlin Fortress. On August 16, Polish forces commanded by Józef Piłsudski counterattacked from the south, disrupting the enemy's offensive, forcing the Russian forces into a disorganized withdrawal eastward and behind the Neman River. Estimated Russian losses were 10,000 killed, 500 missing, 30,000 wounded, and 66,000 taken prisoner, compared with Polish losses of some 4,500 killed, 10,000 missing, and 22,000 wounded.
Józef Piłsudski
Piłsudski's plan called for Polish forces to withdraw across the Vistula River and to defend the bridgeheads at Warsaw and on the Wieprz River while some 25% of the available divisions concentrated to the south for a strategic counteroffensive. The plan next required two armies under General Józef Haller, facing Soviet frontal attack on Warsaw from the east, to hold their entrenched positions at all costs. At the same time, an army under General Władysław Sikorski was to strike north from outside Warsaw, cutting off Soviet forces that sought to envelope the Polish capital from that direction. The most important role, however, was assigned to a relatively small, approximately 20,000-man, newly assembled "Reserve Army" (also known as the "Strike Group", ""Grupa Uderzeniowa""), comprising the most determined, battle-hardened Polish units that were commanded personally by Piłsudski. Their task was to spearhead a lightning northward offensive, from the Vistula-Wieprz triangle south of Warsaw, through a weak spot that had been identified by Polish intelligence between the Soviet Western and Southwestern Fronts. That offensive would separate the Soviet Western Front from its reserves and disorganize its movements. Eventually, the gap between Sikorski's army and the "Strike Group" would close near the East Prussian border, bringing about the destruction of the encircled Soviet forces.