The battle can be divided into 3 phases:
Phase I — Polish offensive towards Stryków, aiming at the flank of the German 10th Army (9–12 September)
Phase II — Polish offensive towards Łowicz (13–15 September)
Phase III — German counterattack and eventual defeat of the Poles, with the latter's withdrawal towards Warsaw and
Modlin (16–19 September)
On the night of 9 September, the Polish Poznań Army commenced a counterattack from the south of the Bzura river, its target being the German forces from the 8th Army advancing between Łęczyca and Łowicz, towards Stryków.
The commander of Poznań Army, Tadeusz Kutrzeba noticed that the German 8th Army, commanded by general Johannes Blaskowitz, was weakly secured from the north by only the 30th Infantry Division stretched over a 30 kilometre defensive line while the rest of the army was advancing towards Warsaw.
The main thrust of the Polish offensive were the units under general Edmund Knoll-Kownacki, known as the Knoll-Kownacki Operational Group (Polish 14th, 17th, 25th and 26th Infantry Divisions).
The right wing of the offensive, in the area Łęczyce, included the Podolska Cavalry Brigade under Col.
L. Strzelecki, and on the left, advancing from Łowicz to the area of Głowno, the Wielkopolska Cavalry Brigade under general Roman Abraham.
These groups inflicted considerable losses on the German defenders from the 30th Infantry Division and the 24th Infantry Division, with some 1,500 German soldiers killed or wounded and an additional 3,000 lost as prisoners during the initial push.
The cavalry brigades supplemented with TKS and TK-3 reconnaissance tanks moved to threaten the flanks and rear of the advancing German units.

The German forces were thrown back approximately 20 kilometres and the Poles recaptured several towns, including Łęczyca and Piątek, and the village of Góra Świętej Małgorzaty.
On 10 September, the Polish 17th Infantry Division met the German 17th Infantry Division at Małachowicze.
The following day Polish forces continued their attack, advancing on Modlna, Pludwiny, Osse and Głowno.

Initially underestimating the Polish advance, the Germans decided on 11 September to redirect the main force of the German 10th Army, the German 4th Army, the reserves of the Army Group South, and aircraft from 4th Air Fleet towards the Bzura.
These forces included the German 1st Panzer Division, German 4th Panzer Division and the newly formed SS Infantry regiment Leibstandarte Adolf Hitler.
German air superiority had a significant impact, making it very costly and difficult for the Poles to move units during the day.
The following day the Poles reached the line Stryków-Ozorków.
That day General Tadeusz Kutrzeba learned that units of Army Łódź had retreated to the Modlin Fortress, and decided to stop the offensive, instead looking to try to break through Sochaczew and the Kampinos Forest to reach Warsaw.

On the morning of 14 September, General Władysław Bortnowski's 26th and 16th Infantry Divisions crossed the Bzura near Łowicz.
 The Polish 4th Infantry Division reached the road linking Łowicz with Głowno.
 At this point however, Bortnowski ordered the 26th Infantry Division to retreat.
He had learned of the withdrawal of the German 4th Panzer Division from the outskirts of Warsaw, and was concerned that this Panzer division posed a threat to his men.

On 15 and 16 September, Army Pomorze took up defensive positions on the north bank of the Bzura.
General Stanisław Grzmot-Skotnicki's group was between Kutno and Żychlin, General Michał Karaszewicz-Tokarzewski's units near Gąbin, and parts of Army Poznań by the Bzura near Sochaczew, were ready to begin their drive towards Warsaw.
To encircle and destroy the Polish forces, the Germans used most of their 10th Army, including two armoured, one motorized, and three light divisions, equipped with some 800 tanks altogether.
The attack from all sides on Polish positions started on 16 September, with the support of the Luftwaffe.
On 15 September Poles were forced out of Sochaczew, a town on the Bzura river, and trapped in a triangle of Bzura, Vistu
The battle can be divided into 3 phases:
Phase I — Polish offensive towards Stryków, aiming at the flank of the German 10th Army (9–12 September)
Phase II — Polish offensive towards Łowicz (13–15 September)
Phase III — German counterattack and eventual defeat of the Poles, with the latter's withdrawal towards Warsaw and
Modlin (16–19 September)
On the night of 9 September, the Polish Poznań Army commenced a counterattack from the south of the Bzura river, its target being the German forces from the 8th Army advancing between Łęczyca and Łowicz, towards Stryków. The commander of Poznań Army, Tadeusz Kutrzeba noticed that the German 8th Army, commanded by general Johannes Blaskowitz, was weakly secured from the north by only the 30th Infantry Division stretched over a 30 kilometre defensive line while the rest of the army was advancing towards Warsaw. The main thrust of the Polish offensive were the units under general Edmund Knoll-Kownacki, known as the Knoll-Kownacki Operational Group (Polish 14th, 17th, 25th and 26th Infantry Divisions). The right wing of the offensive, in the area Łęczyce, included the Podolska Cavalry Brigade under Col. L. Strzelecki, and on the left, advancing from Łowicz to the area of Głowno, the Wielkopolska Cavalry Brigade under general Roman Abraham. These groups inflicted considerable losses on the German defenders from the 30th Infantry Division and the 24th Infantry Division, with some 1,500 German soldiers killed or wounded and an additional 3,000 lost as prisoners during the initial push. The cavalry brigades supplemented with TKS and TK-3 reconnaissance tanks moved to threaten the flanks and rear of the advancing German units.
The German forces were thrown back approximately 20 kilometres and the Poles recaptured several towns, including Łęczyca and Piątek, and the village of Góra Świętej Małgorzaty. On 10 September, the Polish 17th Infantry Division met the German 17th Infantry Division at Małachowicze. The following day Polish forces continued their attack, advancing on Modlna, Pludwiny, Osse and Głowno.
Initially underestimating the Polish advance, the Germans decided on 11 September to redirect the main force of the German 10th Army, the German 4th Army, the reserves of the Army Group South, and aircraft from 4th Air Fleet towards the Bzura. These forces included the German 1st Panzer Division, German 4th Panzer Division and the newly formed SS Infantry regiment Leibstandarte Adolf Hitler. German air superiority had a significant impact, making it very costly and difficult for the Poles to move units during the day. The following day the Poles reached the line Stryków-Ozorków. That day General Tadeusz Kutrzeba learned that units of Army Łódź had retreated to the Modlin Fortress, and decided to stop the offensive, instead looking to try to break through Sochaczew and the Kampinos Forest to reach Warsaw.
On the morning of 14 September, General Władysław Bortnowski's 26th and 16th Infantry Divisions crossed the Bzura near Łowicz.  The Polish 4th Infantry Division reached the road linking Łowicz with Głowno.  At this point however, Bortnowski ordered the 26th Infantry Division to retreat. He had learned of the withdrawal of the German 4th Panzer Division from the outskirts of Warsaw, and was concerned that this Panzer division posed a threat to his men.
On 15 and 16 September, Army Pomorze took up defensive positions on the north bank of the Bzura. General Stanisław Grzmot-Skotnicki's group was between Kutno and Żychlin, General Michał Karaszewicz-Tokarzewski's units near Gąbin, and parts of Army Poznań by the Bzura near Sochaczew, were ready to begin their drive towards Warsaw. To encircle and destroy the Polish forces, the Germans used most of their 10th Army, including two armoured, one motorized, and three light divisions, equipped with some 800 tanks altogether. The attack from all sides on Polish positions started on 16 September, with the support of the Luftwaffe. On 15 September Poles were forced out of Sochaczew, a town on the Bzura river, and trapped in a triangle of Bzura, Vistu
Battle of the Bzura