123: Battle of the Bzura


With the Polish defense collapsing throughout Poland, on September 9th the remnants of Army Poznan and Pomorze would launch Poland’s largest counterattack of the campaign.


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  • British Cabinet Papers - CAB 55/19/15, CAB 65/1/1-65/1/31, CAB 65/3/1-65/3/14, CAB 66/1/38-39, CAB 66/2/20


Hello everyone and welcome to History of the Second World War Episode 123 - The September Campaign Pt. 15 - Battle on the Bzura. This week a big thank you goes out to Johan for the donation and to Sam, Ken, and Mark for choosing to support the podcast by becoming a member. Supporting the podcast gets you access to ad-free versions of all of the podcast’s episodes. Head over to historyofthesecondworldwar.com/members to find out more. After the collapse of Polish defenses in the border regions, there were two primary directions of retreat for Polish troops. Those in northern Poland collapsed back toward the capital of Warsaw, while those in the south would retreat first to the Vistula and then towards Lvov. This episode will focus on the largest group of Polish troops which were retreating in the north, the remnants of Army Poznan and Pomorze. The troops of these two armies would launch the largest Polish counterattack of the entire campaign on September 9th to the west of Warsaw. The counter attack would experience some early success before grinding to a halt. Overall it would not drastically alter the course of the campaign, and this has left the entire operation in one of those areas of the war which is presented in drastically different ways depending on the history that you are reading. Some historians present it as a smart move, catching the Germans by surprise, and while it did not completely change the course of events it was still a worthwhile effort. Other historians just present it as a useless waste of lives and that it was foolish that it was ever considered. In my opinion, the attack never really had a chance of slowing the wider German advance, it was just too late for that, but the operation overall was the best use of Polish troops at the time it occurred. There were so few options available to Polish officers after the first week of the campaign, most units would be forced to retreat and they would find it impossible to stop that retreat once it started. Some kind of counterattack was the other option, and it at least had the opportunity of making a positive impact.

The one positive aspect of the attack that cannot be denied is that the Germans did not anticipate such an action by the remaining Polish troops. By the second week of September German army leadership assumed that the Poles were evacuating as many troops either to Warsaw or further east. They did not expect any major fighting to the west of the Vistula after September 7th. All of this was purely assumption though, they did not really have great information on Polish movements or Polish troop strength, one staff officer would write around this time that “Our information about the Poles is truly wretched.” This caused them to completely discount the possibility of any Polish attack.

On the Polish side the commander of Army Poznan, General Kutrzeba had been advocating for a Polish attack since the very start of the war. In the opening days of the German attack he had wanted to use his troops to attack south against the German units attacking towards Lodz. This request had been denied by the Polish General Staff, and so Army Poznan had retreated to the east along with every other Polish army. The situation changed after Polish leadership had evacuated from Warsaw, and military leaders in northern Poland were largely able to choose their own path over the following days. This included Kutrzeba who would made a few observations about the larger picture. He knew that he had the only Polish army that had made it through the first week of the invasion largely intact, with Army Poznan still having most of its units in good order. He also knew that as Army Poznan and Pomorze were retreating south and east they were running out of space, and there was a real chance that they would be cut off from further retreat to the capital. If this happened, the 150,000 troops of the combined Polish armies would have little to do other than surrender. Kutrzeba would choose a different path, and he would coordinate with General Bortnowski who still commanded what was left of Army Pomorze. The general plan was for Army Poznan to launch the main attack, pushing south to hit the flank of the German units that were pushing hard to Warsaw. This would require attacking across the river Bzura, which is why the battle is called the Battle of the Bzura. While this was happening Army Poznan would try and hold off any German attacks that could threaten the flanks or rear of the attack. After the initial attack both armies would join together in a joint attack to push through any Germans on their way to Warsaw where they would join whatever was left of their units to the Polish Defense Command under General Czuma. There were a few major challenges that the Poles would face in this endeavor. Many of their troops had been in heavy fighting since the start of the invasion, and all of them had spent over a week retreating. They had not been constantly on the move like many Polish units in southern Poland, but discipline and organization were far below what would have been seen before the start of the war. The good news is that regardless of their readiness, there were a lot of Polish troops, 150,000 men spread over 9 infantry divisions and 2 cavalry brigades. They would even have some air support, with Kutrzeba retaining control of his fighter and reconnaissance squadrons even though all other Polish aviation units had been ordered south.

The attacks would started on September 9th. Polish accounts of the start of the attack are full of a single sentiment, they were happy to be doing something other than retreating. One artilleryman would describe his battery as “tired of the nine-day retreat, at last began shelling the enemy. And you should have seen them bustle about their guns!” while one cavalry officer would write “I experienced a very happy moment for the first time in the September campaign: we were no longer retreating.” When the attack started many Polish units would experience a new situation: actually having numerical superiority over the Germans. This was especially true in the center of the attack where 3 infantry divisions and 2 cavalry brigades would attack. In some areas the attack would experience easy success, as the German units were caught completely by surprise and forced to retreat. In other areas the defense would be quite stout. For example in Łęczyca (woe-cheetzah) the initial Polish attack by the Polish 25th Infantry division would be stopped by the German defenders of the 46th Infantry regiment. More units of the 25th division would be brought in later in afternoon, and another attack would be launched to eventually capture the town, but even this success was only possible because the German units were running short of ammunition. On the right flank of the attack Polish cavalry units would attack the town of Uniejów (oon-yey-oov), but it would take until after 8PM before it was fully under Polish control. In general the 9th was a day of success, with all of the Polish units committed to the attack able to push across the Bzura and German units all along this area of the front being in retreat by nightfall. One German staff officer would late write that the 9th was a day where bad news just constantly rolled into headquarters one piece after another. The setbacks of the day were the largest that the German army had encountered since the start of the campaign. There had been areas where the German attacks had not met their goals, there had also been a few small areas where the Polish troops had successfully launched isolated counter attacks, but nothing even close to the scale of the attacks across the Bzura.

On the 10th the attacks would continue, with Polish units trying to continue the successes that had been made on the previous day. The second day of the attack would be critical if it was going to be able to have any sustained success, because less than 24 hours after the attack started the Germans were already reacting. General von Rundstedt had already dispatched the 221st Infantry Division from the Army Group South reserves to move north to provide reinforcements, and they would begin to arrive late on the 10th. This gave the Polish attackers a brief window to continue their attacks, and they would throughout the day. Units of the 25th Infantry would push south from Łęczyca, the 14th infantry division would attack a village called Piatek. Here again the German defenders would mount a solid defense and it would take most of the day before the village was free of German units. The biggest problem for the Polish attack is that, while they were able to make some territorial gains on the second day of the attack, almost without exception the German units in front of them were bending and not breaking. They were able to retreat largely in order, usually only after slowing the Polish attack. This prevented the Polish attack from turning into anything more than a slight adjustment to the front. As night fell the views from the German side of the line were very different than they had been overnight on the 9th. Reinforcements were arriving from the south and the German commander, General Blaskowitz would write: “We have succeeded in presenting the enemy who has crossed the Bzura with a united front, the crisis has passed.”

Even if the Germans were starting to think that the situation was in hand, the Polish troops were not done with their attacks. Kutrzeba would give his order of the day, which would include this quote: “The enemy is in retreat. He is withdrawing from the Warsaw area and is encircled by us. In his rear our fellow countrymen form rebellious gangs. Revolt throughout the Poznan region. Forward to total victory.”

On September 11th the Polish efforts would be redoubled with the addition of multiple divisions from Army Pomorze. 2 Infantry divisions would attack and cross the Bzura near Lowicz (Wah-veetch) and then attempt to continue south. But just south of the river they would run into the German 10th Infantry division which would be able to stop the Polish advance. All along the front of the attack Polish attacks began to run into German units that had been pushed forward to stop them. Blaskowitz would also begin to target specific areas of the front with counter attacks, with the German 17th Infantry division pushing the Polish 17th Infantry Division out of Ozorków in one such counter attack effort. September 11th would also see the German units on the other size of Army Pomorze come into play, with attacks against the western side of Army Pomorze threatening the Bzura attacks which were pushing south. One of the reasons for the limited German response on September 11th was the general lack of mobile troops under Blaskowitz’s command. Most of the armored and motorized units were committed to attacks towards Warsaw, and the German generals did not want to distract them from that effort. The limited number of armored units available were not enough to make a major difference. One German officer of the 23rd Panzer Regiment would record his experiences during the day as “Heavy fire, from trees, from behind haystacks, from the left, from the right and from the front, struck our panzers which advanced without halting. A murderous duel between our panzer and Polish anti-tank guns began. A Polish anti-tank gun, situated behind the corner of a house, was particularly dangerous. Even though one crew after another was killed as a result of our panzer’s machine-gun fire, again and again Polish soldiers jumped out of the house to man the gun. The last man to shoot – and die – at the gun was a Polish lieutenant.” Overall on September 11th the Polish troops had still been able to make some headway in their attacks, they had captured a bit more territory and a few more villages, but resistance was clearly stiffening.


Even before any major German counter attack occurred, the Luftwaffe would shift its focus from other areas of the front to the Polish troops near the Bzura. German fighters and bombers would begin to focus their efforts on attacking Polish troops movements behind the line, with these air attack accelerating as the Polish units began to retreat from some of their gains made over the previous days. There were still a few Polish fighter squadrons flying over the attacks, and on the 12th they would be able to shoot down two German He-111 bombers, but this was just a small fraction of the German aircraft that were active over the front. Kutrzeba would write “Every movement, every grouping, all the routes of advance were subjected to a pounding from the air. Hell on earth had begun. The bridges were destroyed, the fords jammed, the columns waiting to cross destroyed by bombs.” Polish attacks continued though, but gains were becoming very costly. One attack by the 4th Infantry division and a cavalry brigade would make little headway after a full day of attacking the German 10th Infantry division. The general slowdown of Polish advances, and how costly any additional gains were becoming would push Kutrzeba to move to the final phase of the attack. Over the following days instead of continuing to push south the Polish units would begin to attack east, which would allow them to approach Warsaw from the west. Reaching the capital was not a sure thing though, and if they were to reach Warsaw they would have to make their way through a very narrow narrow area south of the Vistula, and it would require moving through the Kampinos forest. The Germans were not going to make this movement easy though. The Luftwaffe would only increase its strength over the front, and on September 13th additional German reinforcements, including armored and motorized units would begin to arrive.

When these units began to arrive the German troops started their counter attack. The exact nature of this counterattack was different depending on where you were on the front. The general plan was simply to push the Polish units back from the gains they had made over the previous days. In some areas this attack began as early as September 13th, but in others it would have to wait several more days. The differences were generally dictated by exactly when specific reinforcements arrived. The two most important units were the 1st and 4th Panzer divisions, which were diverted from other efforts specifically to deal with the new situation that had developed around the Bzura. While they were waiting for newly arriving units to position themselves from the counterattack effort, the German commanders also had to contend with the slightly bit of confusion caused by the units around the Bzura operation being from different Army Groups. Those on the northern side of the river were attached to Army Group North, those to the south Army Group South. The German Army Groups were generally better at coordinating than the Polish Armies had been, but such an arrangement always introduces additional friction. The Polish units needed anything to give them even a slight advantage, because their time was running out by the hour. The German efforts would quickly cut off the possibility of a Polish retreat to Warsaw, leaving them fully surrounded. After September 14th, over the next few days, there was a general trend of Polish units losing ground as they tried to push east. There were some successes, even if they were always fleeting. For example there would be stout defense against Panzer Regiment 35 which would cause the German regiment to lose a quarter of its tanks. The Polish break out attempts would come to a crescendo on the night of September 18th. During the night most of the remaining Polish troops in the Bzura pocket attacked to the east in a final attempt to make it to the Kampinos Forest. The Forest was not large, less than 400 square kilometers, and it was not going to be easy for any army to move through it. It was in the area between the Vistula and Bzura rivers and it was full of marshes, waterways, and broken ground. Some Polish units would not make it to the forest, and they would be forced to either surrender or continue a hopeless resistance the next day. One German officer would write “They’re probably determined to give up their lives but not their honour. We cannot deny them our admiration.” But any resistance by September 19th, for any units not actively continuing their push for Warsaw, was a hopeless effort. Other units were able to stick together long enough to make it to cover, but then some of them would not be able to hold it together. One Polish officer would write in a diary that the situation in his unit could be described as “Utter confusion among the men. Dejection. Tiredness.” The high estimates are that 50,000 Polish soldiers would make it to Kampinos, but far less would make it out the other side and to Warsaw. Kutrzeba and several of his officers would make it through with various units, but they were the lucky ones. Bortnowski and many of his troops would make it to the Forest only to be captured by German units.

The exact number of Polish troops that died, were captured, or escaped the German encirclement is difficult to determine. The number of Polish troops who would be killed was probably around 16,000, but the biggest problem is how many Poles died during those final days of the attack. The exact number captured by the Germans is equally fuzzy, the German estimates which is about all we have to go on put the number at around 120,000 or maybe a bit higher. The German casualties were much lower, with the 8th army suffering the greatest number at around 9,000, with only about 2,000 of those being deaths. The vast majority of these German casualties came during the early fighting when they were caught off guard by the Polish attack, with most of the Polish casualties coming on the other wide of the counterattack, in the final days as the German vise began to squeeze them.

How can we evaluate the Polish counterattack? At the start of this episode I mentioned that the Polish attack did not completely reshape the course of the campaign that was happening around it. But that doesn’t mean it was not successful. It would draw the attention of 19 German divisions at a time when in other areas of Poland the biggest problem that many German units had was how far they could march in a day. The Bzura counterattack would also be one of the most successful Allied counterattacks until really some point in the North Africa campaign in 1941. Although that comparison probably says a lot more about the events of 1940 than anything else. The casualty figures were massive, but there were no other options for the Polish units that found themselves trapped to the West of Warsaw after the first week of September. Those involved in the fighting would have their own evaluations, Kutrzeba would later write that the attack could have achieved much more if things had fallen a bit differently, and that it ‘could have been won by us, or at any rate ought not to have been lost so bloodily’. In German evaluations of the fighting, they believed that if it had only occurred a few days earlier the results could have been very detrimental to their advance on the capital. Just a few days earlier and it would have been more difficult to concentrate all of the reinforcements against the 9 Polish divisions on the Bzura. Given the state of the Polish military by September 10th, and its inability to even slow the German advance, even just buying Warsaw a few more days is almost a triumph. I hope you will join me next episode which will continue to cover the German advance on the Polish capital.