Jan Kruszewski Operational Group "Sieradz" (Grupa Operacyjna Sieradz) under gen. Franciszek Dindorf-Ankowicz Operational Group "Śląsk" (Samodzielna Grupa Operacyjna Śląsk) under gen. Jan Jagmin-Sadowski (on September 3 renamed to Operational Group "Jagmin" (Grupa Operacyjna Jagmin)) Eastern Operational Group (Wschodnia Grupa Operacyjna) under gen. Mikołaj Bołtuć (on September 9 renamed to Operational Group "Bołtuć") (Grupa Operacyjna Bołtuć) In addition, during the invasion of Poland in 1939, several other corps-sized units were formed or improvised. All of them were named after their commanding officers: Operational Group Dreszer (Grupa Operacyjna Dreszer) under Rudolf Dreszer Operational Group Orlik-Łukoski (Grupa Operacyjn Orlik-Łukoski) under Kazimierz Orlik-Łukoski Operational Group Grzmot-Skotnicki (Grupa Operacyjna Grzmot-Skotnicki) under Stanisław Grzmot-Skotnicki Operational Group Kareszewicz-Tokarzewski (Grupa Operacyjna Karaszewicz-Tokarzewski) under Michał Karaszewicz-Tokarzewski Operational Group Zaulauf under (Grupa Operacyjna Zulauf) Juliusz Zulauf There were also several operational groups created by the Polish People's Army (Ludowe Wojsko Polskie) after the war in the years 1946-1947. See also Polish army order of battle in 1939