The defense of Warsaw, a significant battle during the invasion of Poland in September 1939, involved Polish forces and civilians against German Wehrmacht and Luftwaffe units. Despite improvised defenses and evacuations, led by General Walerian Czuma and supported by President Stefan Starzyński, Warsaw resisted initial German attacks. The city's defense was bolstered by failed German assaults and Polish counterattacks, leading to continued bombardment. Ultimately, Warsaw managed significant resistance until September 22, when remnants of the Poznań and Pomorze armies arrived.