The Battle of Chojnice occurred during the 1939 German invasion of Poland on the first day of the hostilities, 1 September. A detached unit from the Polish army Chojnice Detached Group under Colonel Tadeusz Majewski, part of the Czersk Operational Group under Stanisław Grzmot-Skotnicki, was assigned the task of defending the city of Chojnice, a major regional communications center, to protect the southern flank of Army Pomorze.