The Battle of the Bzura was a World War II battle fought between the German Army and Polish forces from September 9 to September 19, 1939, in Poland. It took place during the German Invasion of Poland, near the Bzura River, west of Warsaw, Poland. The Battle of Bzura was the largest German September Campaign battle, which broke out with a Polish attack on the German 8th Army flank. It first gained initial success but eventually ground to a halt and disintegrated under a concentrated German counterattack.
On September 1, 1939, Germany had marched into Poland, triggering World War II, initiating Operation Case White, Fall Weiss in German. Combining the demolishing power of the Stukas bombers with armored divisioned reinforced by mechanized infantry units, the German Armies made rapid progress, piercing deep into Polish territory. By September 9, the German 8th Army was on the move towards Warsaw. It was secured from the north by only the 30th Infantry Division that had spread out along a 20-mile, defensive line.
Polish Army Poznan and Army Pomorze, retreating from the border area of the Polish Corridor, attacked the flank of the German 8th Army. The Polish main attack was concentrated in the area of Stryków. The Podolska Cavalry Brigade was the right wing of the offensive, and on the left was the Wielkopolska Cavalry Brigade. During the initial push these groups inflicted considerable losses on the German 30th Infantry Division which sustained 1,500 casualties and the loss 3,000 soldiers that had been taken prisoner. The Polish also used TKS and TK-3 reconnaissance tanks.
The Polish 26th and 16th Infantry Divisions of Army Poznan crossed the Bzura river near Lowicz as the 4th Infantry Division of Army Pomorze reached the road, connecting Lowicz with Glowno. On hearing news that the German 4th Panzer Division had just withdrawn from its positions on the outskirts of Warsaw and was heading towards the Polish forces, the Polish General Bortnowski ordered the 26th Infantry Division to retreat and take up defensive position on the northern bank of the Bzura, along with the rest of the Army Pomorze.
In order to encircle and destroy the Polish Armies, the Germans used most of their 10th Army, which included three light, two armored, one motorized divisions, which were equipped with some 800 tanks altogether. On September 16, with the support of the Luftwaffe, the Germans launched an assault from all sides on Polish positions. The German 1st Panzer Division, after crossing the Bzura between Sochaczew and Brochów, engaged the Polish 25th Infantry Division, destroyed it and managed to capture Ruszki.
On September 17, Army Poznan attacked the German forces in order to break out of the encirclement between Witkowice and Sochaczew, while Army Pomorze simultaneously marched towards the villages of Osmolin, Kierozia and Osiek. Then the Germans began their push southwards, along both banks of the Bzura river, supported by heavy artillery and 300 aircraft. German howitzers, deployed on the high ground of the Vistula’s right bank, pounded the Polish positions for the rest of the day. After two days of vicious fighting, the Polish attempt to break out of the German encirclement failed. In the next couple of days the Germans mopped up the scattered pockets of resistance, putting an end to the Battle of Bzura.