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.
Siege of Warsaw (1939)
On September 11 the Polish Commander in Chief ordered that Warsaw was to be defended at all costs, despite the possible heavy casualties and civilian losses. The following day the forces of German 3rd Army (under General Georg von Küchler) broke through Polish lines along the Narew river and started its march southwards to cut off Warsaw from the east. It was assaulted by cavalry units under Władysław Anders, but after heavy fighting the Polish counter-offensive failed and the forces were withdrawn to the south. Other Polish units fighting under General Juliusz Zulauf near the Narew River area retreated and reached Warsaw on September 14. They were incorporated as the core of the defence forces of the borough of Praga district.