The Battle of Tuchola Forest was one of the first battles of World War II, during the invasion of Poland. The battle occurred from 1 September to 5 September 1939 and resulted in a major German victory. Poor Polish command and control, as well as German numerical and tactical superiority, allowed the Germans to manage to cripple Poland's Armia Pomorze and, by breaking through the Polish Corridor, to connect mainland Germany with East Prussia.

The Battle of the Border refers to the battles that occurred in the first days of the German invasion of Poland in September, 1939. The series of battles ended in a German victory, as Polish forces were either destroyed or forced to retreat.