Battle of Chojnice during the 1939 German invasion of Poland occurred on the first day of the hostilities, 1 September. A detached unit of the Polish army, Chojnice Detached Group under col. Tadeusz Majewski, part of the Czersk Operational Group under Stanisław Grzmot-Skotnicki, was tasked with defending the city of Chojnice, a major regional communications center, to protect the southern flank of Army Pomorze. The Polish forces managed to repulse German attacks until 1600–1700 hours, when they received order to fall back towards Rytel (further continued on the night of 1 and 2 September). Polish forces managed even to destroy an armoured train.