The strongest Polish army at that time was the Pomeranian group, which had meanwhile coped with its withdrawal from the corridor. However, the Poznan army under Major General Kutrzeba, cut off in the west, was completely intact. Both armies united at the under Bzura and planned to attack the Germans on their advance to Warsaw into the flank.
On 9 September the XIXth Panzer Corps under Guderian, with four fast divisions, became the first independent tank unit of history to attack with the aim of fortress Brest Litovsk. The corps arrived there on 17 September as a close formation without regard to the flanks and rear connections.
Meanwhile, the Polish armies on the Bzura attacked in the evening the open flank of the German 8th Army during their march on Lodz. The German army was forced to break off its advance on Warsaw in order to fend off the Polish attacks.
This resulted in the greatest battle of the Polish campaign and even the already conquered city of Lodz had to be temporarily evacuated by the German troops. At the Bzura the Poles resisted the German attacks and had to be thrown back step by step.
Only on September 18 did the Polish resistance diminish and the trapped Polish troops attempted to break out to Warsaw until September 23. Finally, 12 Polish divisions were destroyed in the Battle of Bzura (170,000 prisoners of war) and thereafter remained no significant Polish troops west of Warsaw, except for isolated fortresses.
On September 11, the resistance of the Prussy army near Random collapsed and 60,000 men marched into captivity there as well. Warsaw was also sealed off from the east.
On the same day, the Army Group South gave its 10th Army the order to invade deep into eastern Poland as far as Lublin, while the 14th Army, which stood further south and was strengthened with strong tank units, was to reach Lemberg (Lov or Lviv) in order to thwart a Polish retreat to Romania.
However, this undertaking could not be completed, since on 17 September – surprisingly for both the Poles and the Germans – the Red Army invaded eastern Poland with the Belarusian Front (Kovalev) and the Ukrainian Front (Timoshenko).
Stalin was now forced to hastily secure the territory granted to him in the German-Soviet Treaty of 23 August 1939.
That same evening, the Polish government and the army leadership left their country and were interned in Romania.
The invasion of eastern Poland by the Red Army forced the Wehrmacht to break off the battles of Lviv and Tomaszov on September 20 and withdraw behind the demarcation line agreed with the Soviets. The Polish General Langner in Lviv then capitulated to the Russians on 22 September.
Also, on September 20, the Polish reserve army at Lublin was trapped and immediately surrendered with 60,000 men.
The capital Warsaw, declared to a fortress, with 180,000 defenders, was completely encircled and besieged since 22 September. From 24 September, the city was continuously bombed by the German Air Force and by artillery.
On Thursday, 28 September 1939, the Polish garrison of Warsaw surrendered and General Rómmel with 120,000 defenders marched into captivity.
On 28 September 1939, however, the Germans and Soviets agreed on a new demarcation line and renounced the retention of a Polish ‘residual state’. Therefore, German troops had to march into parts of the just evacuated area again and fight against the Polish troops still there.
The next day the Modlin fortress surrendered, on 1 October the 4,000 Polish defenders of the Hela peninsula capitulated, and finally on 6 October 1939 the last 16,800 men under Major General Kleeberg near Kock.
On October 3, Hitler received the Victory Parade in Warsaw.
About 120,000 Polish soldiers were able to escape across the Hungarian or Romanian border and soon fought again on the allied side as Polish Armed Forces in Exile.
Over 700,000 Polish soldiers were taken prisoner of war by the Germans, and the Red Army claimed to have taken 217,000 prisoners of war.
The Polish losses could not be determined exactly and were estimated at about 200,000 men, including 66,000 killed.
The deliberate cavalry attacks of Polish Uhlans on German tanks were probably only existed in Nazi propaganda. At least not a single such case can be witnessed, although it may have happened that a lance attack on infantry led to an unintended collision with armored vehicles.
The German losses in the Polish campaign amounted to 10,572 killed, 3,404 missing and 30,322 wounded. In addition, 217 tanks and 283 aircraft were lost.
The Red Army lost 737 dead and 1,859 wounded.
It is certain, however, that in comparison to the trench wars of the First World War, the losses on both sides were clearly lower by the modern movement war and the duration of the fights was considerably shortened.
In Poland itself, on 3 September 1939, the riots against the German minority reached their climax. Every third inhabitant of Poland belonged to a minority, which represented an enormous risk for the Poles in a conflict. Not only did the Poles conquer large areas with Belarusians and Ukrainians in their attack on Lenin’s Bolshevik Russia after the First World War, they also annexed the old Lithuanian capital Vilnius in 1920 and were granted the old Prussian provinces of West Prussia and Poznan and large parts of Galicia in the Treaty of Versailles.
Already since German-Polish relations had deteriorated because of Danzig (Gdansk) and the question of the corridor between Pomerania and East Prussia in March 1939, the pressure on the German minority began to increase. Thus the German ambassador at Warsaw had to report that the Polish government, thanks to the British ‘blank power of attorney’, obviously no longer considered it necessary to show consideration for the German minority. The Polish voivode of Silesia, for example, speaks openly that the Poles will burn the eyes out of the Germans and rip out their tongues before they are chased across the border.
Some 3,500 German citizens were murdered. Most of the victims – men, women and children – were shot on 3 September 1939 near Bromberg (Bydgoszcz). The reason for this was that German civilians allegedly fired at Polish troops. However, the ‘Deutsche Rundschau in Polen’, which appeared in Bydgoszcz the day before, had already pointed out that the German minority was under Polish law and called for no action to be taken that would corrupt the ethnic group.
In retaliation, apart from isolated attacks by German soldiers, there were also ordered executions by SS or police units.
However, a planned or ordered genocide was not on the agenda at that time. However, the Polish attacks, which were overrated by Nazi propaganda, subsequently served as a pretext for implementing an extremely harsh occupation policy in Poland, which was no longer commensurate with the extent of the crimes committed against ethnic Germans.
At the time of the Polish campaign, however, there were still no instructions for particularly tough action, since even Hitler had no idea what he wanted to do with Poland. Originally, his actions were aimed at regaining the German territories lost in the Treaty of Versailles. Even the alleged, long-term ‘planning of a war of aggression’ against Poland, as it was accused in the Nuremberg Trial, is largely taken out of the air.
Because the politician and leader Hitler was a pragmatist with the nature of a player who tried to get the best out of an existing situation or opportunity. It is well-known that ‘opportunity makes thieves’ and extreme racists under the sword of Damocles of a possible defeat since autumn 1941 and with the help of the cover of war no longer shy away even from genocide.
The original idea of how to proceed with Poland after the annexation of the German eastern territories was to leave a controlled Polish residual state in existence, similar to the satellite state of Slovakia. This should also make it possible to end the state of war towards the West. The Soviets, however, did not want a Polish residual state to exist at all, so that the ‘Generalgouvernement’ (General Government) was created.
It was not until 17 October 1939 that Hitler and Keitel decided in a meeting that Poland should not become a ‘model country’. The aim was to prevent Polish intelligentsia from calling for resistance. Instead, the Polish labor potential should be used at a low level for German needs.
The area should also be usable for the future as a military deployment area – with only the Soviet Union could be considered here – and therefore roads, railways and communications should be kept in order. After all, the rest of Poland was to serve as a ‘catchment basin’ for Jews and Poles from the Reich territory and the re-annexed provinces.
On 23 November 1939, the Wehrmacht (General of the Artillery Petzel, military district command XXI in Posen, Ic86/39) complained in writing about the activities of SS formations in the annexed provinces of Poznan, where shootings had taken place in almost all major towns. Poles were also arrested and interned, and their property was often plundered. There were also numerous assaults against Polish Jews, with ethnic Germans among the victims themselves.
On 21 November 1939 a German officer wrote in a letter from eastern Poland that an ‘organised minority’ committed the worst crimes there under ‘highest tolerance’, against which the troops were not allowed to intervene. These actions can no longer be excused by the crimes committed against the ethnic Germans and if these people are not stopped, their own people will also be affected by such acts, and it will fall back on themselves.