Germany cuts the Polish Corridor

On 4 September 1939, the fourth day of the German invasion of Poland, the battle for the Polish Corridor came to an end. The troops of the German 4th Army, which had set out from Western Pomerania on 1 September, passed through the Tuchola Forest, reached the Vistula between Świecie and Chełmno and made contact with the 3rd Army, which was advancing from East Prussia on Grudziądz. The strip of Polish territory that since 1920 had separated East Prussia from the rest of the Reich had been cut. The Polish Pomorze Army under Major General Władysław Bortnowski lost most of two infantry divisions in the fighting and was forced to fall back to the south.

The meeting of the 3rd and 4th Armies is usually dated to 4 September. The date is a convention. The leading units of General Heinz Guderian’s armoured corps had reached the Vistula as early as 2 and 3 September, and by the evening of 3 September the Polish units in the Tuchola Forest were completely surrounded. On 4 September the Germans occupied Grudziądz, which the Poles had abandoned, and were destroying the last Polish groups trying to break through to the Vistula. The fighting in the pocket died down by 5 September, and Polish historiography takes that date as the end of the Battle of the Tuchola Forest.

The Corridor and its defence

For Hitler the Corridor had been one of the principal objectives from the outset. In the autumn of 1938 and the spring of 1939 Germany had demanded an extraterritorial motorway and railway line across Pomerania to East Prussia, and Poland had refused. Under Case White, the task of cutting the Corridor and linking the Reich with East Prussia was given to Army Group North under General Fedor von Bock. The 4th Army of General Günther von Kluge was to strike from the west, and part of the 3rd Army of General Georg von Küchler from the east. The main striking force of the 4th Army was Guderian’s XIX Army Corps: the 3rd Panzer Division of General Leo Geyr von Schweppenburg and the 2nd and 20th Motorised Infantry Divisions. On its right flank advanced the II Corps of General Adolf Strauß. Guderian knew the ground. He had been born in 1888 in nearby Chełmno, and before 1919 Prussian troops had exercised in the Tuchola Forest.

The Polish command knew that the Corridor was a trap. It was narrow, flanked by Reich territory to the west and east, and there was not a single bridge over the Vistula between Grudziądz and Fordon. Under Plan West, the Pomorze Army was to cover the approaches to Bydgoszcz and Toruń and merely delay the enemy in the depths of the Corridor. Political considerations, however, required strong forces to be pushed far to the north. There were fears that Germany would seize Gdańsk (Danzig) and declare the matter settled before the war had properly begun. In the last days of August, therefore, the Intervention Corps, including the 27th Infantry Division of Brigadier General Juliusz Drapella, was sent to the area of Starogard and Kościerzyna, and the 9th Infantry Division of Colonel Józef Werobej, a staff-trained officer, was moved north to cover this operation. Bortnowski considered this deployment a mistake and pressed the General Inspectorate of the Armed Forces in vain for permission to withdraw the troops. On the western edge of the Corridor stood Operational Group Czersk of Brigadier General Stanisław Grzmot-Skotnicki with the Pomeranian Cavalry Brigade, and on the right bank of the Vistula, facing East Prussia, Operational Group East of Brigadier General Mikołaj Bołtuć with the 4th and 16th Infantry Divisions (PL).

1 September: the Brda and Krojanty

The Germans crossed the border at dawn on 1 September. In the north they tried to seize the Vistula bridges at Tczew by surprise, bombing the positions of the Polish sappers and sending a train towards them, but the sappers blew up the bridges in the morning. In the south, near Chojnice, the 20th Motorised Division met resistance from a rifle battalion and National Defence battalions, and the armoured train with which the Germans had hoped to take the station by surprise was destroyed. The main blow, however, fell on a thinly held gap in the Polish defences between Sępólno and Pruszcz. The 3rd Panzer Division passed through it almost unhindered and in the afternoon, because the Polish demolitions came too late, captured an intact bridge over the Brda near Sokole-Kuźnica. Polish attempts to retake the crossing during the night failed. From then on nothing serious stood between the German tanks and the Vistula.

That same evening saw the most famous action of the battle. To help the Polish infantry withdraw from Chojnice behind the Brda, the 18th Pomeranian Uhlan Regiment was ordered to strike at the rear of the advancing Germans. The regiment’s commander, Colonel Kazimierz Mastalerz, led two squadrons with two additional platoons by a roundabout route through the forest. At around 7 p.m., near Krojanty, the uhlans came upon a resting battalion of the German 76th Motorised Infantry Regiment and charged it with sabres. The German infantry scattered, but when the cavalrymen rode out into an open clearing they came under fire from German armoured cars concealed nearby. According to Polish findings, of the more than two hundred men who charged about 25 were killed, among them Mastalerz and the commander of the 1st Squadron, and about 50 were wounded. The charge achieved its purpose: it took the Germans by surprise, held them up for several hours and allowed the infantry to withdraw across the river. Guderian recalled that that evening he found his staff setting up an anti-tank gun because a Polish cavalry attack was expected.

From this action was born a myth that would endure for decades. When Italian war correspondents were brought to the battlefield the next day, they saw dead uhlans and horses lying beside German armoured vehicles. Thus arose the story of Polish cavalry charging tanks with sabres. It was seized upon by German propaganda, which portrayed the Poles as a brave but backward and reckless nation. Just such a scene appeared in the 1941 propaganda film Kampfgeschwader Lützow. After the war the myth was also perpetuated by Soviet propaganda and by some of the literature and cinema of communist Poland, among them Andrzej Wajda’s Lotna of 1959. In reality Polish cavalry in 1939 mostly fought on foot, using the horse chiefly as a means of rapid movement. It had artillery and anti-tank rifles, and mounted charges were rare and directed against infantry or cavalry, not against tanks.

2 and 3 September: encirclement

On 2 September the 3rd Panzer Division turned east and pushed through the Tuchola Forest towards Świecie. General Bortnowski ordered the 9th and 27th Infantry Divisions to launch a joint breakout attack, but command in the Corridor was already disintegrating. Orders arrived late or not at all, telephone communications kept breaking down, and in the space of a single day the 27th Division received three different orders. The divisions attacked separately and without contact with each other. The 27th Division, after fierce fighting at Świekatowo and Tuszyny, was stopped by German tanks, and the 9th Division tried in vain to break through to the south. In the fighting near Klonowo Lieutenant Heinrich von Weizsäcker, son of the state secretary at the German Foreign Ministry, was killed. His younger brother Richard, President of the Federal Republic of Germany from 1984 to 1994, served in the same regiment.

On the other side of the Vistula the German XXI Corps of the 3rd Army forced the Osa river on 1 and 2 September and drove back the 16th Infantry Division, in which panic broke out. A night counter-attack by the 4th Infantry Division regained some ground, but the Osa line could not be restored. Grudziądz was under attack from several directions.

On 3 September the German XIX and II Corps reached the Vistula. The 3rd Panzer Division closed the ring on a line from Świecie to the settlement of Grupa, while the motorised divisions sealed it from the west and north. The encircled Polish units were concentrated in the woods near Franciszkowo, Krupocin and Bramka, without anti-aircraft cover and under constant air attack. Panic set in. Some soldiers broke through in small groups to the Vistula and swam across; others were taken prisoner. The Pomeranian Cavalry Brigade, at the cost of heavy losses, broke through the ring several times and rejoined the army’s main forces, while the 35th Infantry Regiment of Colonel Jan Maliszewski (PL) was the only unit to remain intact, and on 5 September it reached its own lines. At around 8 p.m. Bortnowski reported to the Commander-in-Chief, Marshal Edward Rydz-Śmigły, that all units north of Bydgoszcz could be regarded as lost. That same day in Bydgoszcz, through which stragglers and supply columns were streaming, there was shooting followed by Polish reprisals against local Germans, one of the most contested episodes of the campaign. On the eastern bank of the Vistula the Polish garrison abandoned Grudziądz on 3 September, blowing up the bridges behind it, and during the night of 3–4 September Operational Group East began to withdraw southwards.

4 September: the link-up

By 4 September the Corridor was in German hands. Troops of the 3rd Army entered Grudziądz, while on the 4th Army’s side the last Polish groups in the pocket were being destroyed. An improvised detachment gathered by the 9th Division’s artillery commander fought all day for the barracks at Grupa before its men began to slip away towards the Vistula in small groups. The divisional commander, Colonel Werobej, cut off from his units, managed to break through and reported to army headquarters only on 12 September near Kutno. The Reich and East Prussia once again had a land connection, and the German command could move troops freely between the two parts of Army Group North.

According to Guderian’s memoirs, his corps lost 150 killed and 700 wounded in the fighting for the Corridor. Polish losses were incomparably greater. The 9th Infantry Division effectively ceased to exist, and according to Bortnowski’s report about three infantry battalions and five artillery batteries escaped from the 27th Division. Polish studies put the 27th Division’s losses at about a third of its infantry and half of its artillery, and several thousand soldiers were taken prisoner. On 5 September Adolf Hitler visited Guderian’s corps (some sources say 6 September). Guderian showed him round the battlefield near Świecie and Plewno. When Hitler, seeing the wrecked Polish artillery, asked whether it was the work of the dive-bombers, Guderian replied proudly that it was the tanks.

Why it happened

The defeat in the Corridor stemmed above all from the deployment. Three large Polish formations – the 9th and 27th Infantry Divisions and Operational Group Czersk – stood deep inside a narrow strip of land that the enemy could cut with a single blow, with the bridgeless Vistula behind them and enemy territory on both sides. This deployment was dictated by political rather than military considerations: the aim was to show that Poland was defending Pomerania and its interests in Gdańsk. The troops were also still mobilising and regrouping when the Germans struck. To this were added German superiority in armour and in the air, and the breakdown of communications, which left the divisions fighting separately. General Bołtuć was later said to have spoken of Bortnowski with great bitterness, but most of the army commander’s subordinates, as well as later historians, pointed out that his room for manoeuvre had been taken away by decisions made in Warsaw.

At the same time the Polish soldiers in the Tuchola Forest fought tenaciously in many places. At Chojnice, on the Brda, at Klonowo and Świekatowo they inflicted losses on the Germans and slowed their advance, and around two-thirds of the Pomorze Army escaped destruction. The names “Bory Tucholskie” (Tuchola Forest) and “Krojanty” are inscribed on one of the plaques of the Tomb of the Unknown Soldier in Warsaw.

Place in the war

Cutting the Corridor was the Wehrmacht’s first great operational success of the war. Pomerania, over which Hitler had been in dispute with Poland since the autumn of 1938, fell into German hands within four days. Repression followed at once. On 5 September the Wehrmacht entered Bydgoszcz, and in occupied Pomerania the Einsatzgruppen, units of the Selbstschutz made up of local ethnic Germans, and SS formations began mass executions of the Polish intelligentsia, clergy and Jews, which Polish historians call the Pomeranian crime (PL). In October Pomerania was incorporated into the Reich as part of the Reichsgau Danzig-West Prussia.

Militarily, victory in the Corridor freed German forces for further operations. Guderian’s corps was transferred through East Prussia to the eastern wing of the front, from where over the following days it struck through Wizna towards Brest, deep into the rear of the Polish defences. The remnants of the Pomorze Army fell back southwards through Toruń and Włocławek, and on 9 September General Bortnowski placed himself under the command of General Tadeusz Kutrzeba. The two armies, Poznań and Pomorze, fought the largest battle of the campaign on the Bzura. The myth of the charge against tanks survived the war as one of the most enduring stereotypes about September 1939, although historians have long shown that at Krojanty the uhlans charged infantry and carried out the task they had been given.