On 1 September 1939 Adolf Hitler issued orders for "Fall Weiss" (Case White) to be implemented and the "Wehrmacht" attacked Poland. was placed under the command of the 4. "Flieger Division" (4th Air Division) under the command of General Alfred Keller. The "Flieger Division" was subordinated to "Luftflotte" 4. KG 55 flew attacks against Polish Air Force airfields on 3 September, after being left out of the campaign's first two days. The "Geschwaderstab" and I./KG 55 were ordered to Maerzdorf/Ohlau and II./KG 55 was moved to Rosenborn. Whilst there the crews listened to operational experiences from the Dornier Do 17-equipped "Kampfgeschwader" 4.