The Warszawa Army (Polish: Armia Warszawa) was one of the Polish armies to take part in the Polish Defensive War of 1939. Created on 8 September, eight days after the invasion begun, it was an improvised formation charged with the defence of the Polish capital of Warsaw (Warszawa).
To defend the Polish capital Warsaw in the face of breakthrough by the German forces.
On 3 September 1939 the Minister of the Army (Min. Spraw Wojskowych), general Tadeusz Kasprzycki, ordered general Walerian Czuma (the Commander of the Border Guards - Straż Graniczna) to organize a force to defend the city of Warsaw against a German attack. The city had been under constant attack by the Luftwaffe since the early morning of 1 September. Initially the only organized units available to him were four infantry battalions, anti-aircraft artillery and anti-aircraft machine guns detachments under colonel Kazimierz Baran, composed mostly of fire-fighter brigades and volunteers supervised by colonel Tadeusz Bogdanowicz and Julian Kulski, the deputy president of Warsaw. The AA artillery had 86 pieces of anti-aircraft artillery, as well as an unknown number of anti-aircraft machine guns. In addition there was an air force Pursuit Brigade which was equipped with 54 fighter aircraft. On the 5 and 6 September the air force and 11 batteries of anti-aircraft artillery were withdrawn to Lublin. Initially however parts of various army units, primarily of Łódź Army, retreating before the onslaught of German armor units, were added to his force.
On 8 September General Juliusz Rómmel, the commander of the Łódź Army who had become separated from his operational units, arrived in Warsaw with his staff. The chief of staff of the Polish Armed Forces, general Wacław Stachiewicz (then in Brześć), appointed him the overall commander of all forces defending Warsaw, including the Warsaw Defense Force, the Modlin Fortress and the army units immediately south and north-east of Warsaw