The 'Battle of Kałuszyn' was fought by German and Polish forces within the context of 'Wess' (i) around the town of Kałuszyn near Mińsk Mazowiecki in Poland (11/12 September 1939).
Following the battle for Poland’s western borders, the forces of General brygady Wincenty Kowalski, commander of the Polish 1st Legions Division and the 'Wyszkow' Operational Group, began a steady withdrawal and undertook delaying actions in the area to the north-east of Warsaw. Following the Battles of Pułtusk and Różan, the 1st Legions Division, reinforced by the units of the 'Wyszków' Operational Group, arrived in the area of Mińsk Mazowiecki. Here they were overrun by Generalleutnant Max Bock’s 11th Division, part of General Walter Petzel’s I Corps of General Georg von Küchler’s 3rd Army within Generaloberst Fedor von Bock’s Heeresgruppe 'Nord', which took the town and surrounded the Polish forces.
The Polish aim was now to retake the town and break through the German encirclement before this latter could be reinforced by armoured forces and its resistance thereby stiffened. After a short artillery preparation, the battle began during the night with a Polish assault on the villages surrounding the town. The Polish forces managed to break through the positions of Oberst Friedrich-Georg Eberhard’s 44th Infanterieregiment, which was disorganized and had underestimated the Polish forces still present in the area.
At one point a Polish commander ordered the 4th Squadron of the 11th Uhlan Regiment to advance towards the town itself. The order was mistakenly understood as an order for a cavalry charge and the 85-man squadron charged the German positions with drawn sabres, breaking through to the town despite suffering the loss of 33 of its men killed. The Polish infantry followed into the breach in the German defences and by the early morning the town had been liberated and the German division forced to retreat.
The losses were significant on each side. The commanding officer of 44th Regiment, Major Krawutschke, committed suicide. In the course of the heavy fighting, the town was almost completely destroyed, and most of the town’s substantial Jewish population was later deported by the Germans to the Warsaw ghetto or Treblinka extermination camp.