A city of strategic importance

Among the units stationed in the nearby Polish Corridor (a key German objective as it’s capture would unite East Prussia with the rest of Germany) were the 9th, the 15th, and the 27^th Polish Infantry Divisions along with the Pomeranian Cavalry Brigade.

View of Grudziadz between 1914 and 1918

National Library of Poland

The Polish High Command had been anticipating a German backed uprising occurring in the Free City of Danzig and so in mid-August, had moved the 27^th Infantry Division and the Pomeranian Cavalry further north to Chojnice and Starogard Gdański to counter this. However, the sudden German invasion of Poland on 1^st September found both units in the corridor and vulnerable to attack.

To the East of the Vistula River, General Günther von Kluge and the German 4^th Army stood facing the city of Grudziądz, which was defended by Operational Group East under the command of General Mikołaj Bołtuć. At his disposal, he had the 4^th (commanded by Colonel Tadeusz Lubicz-Niezabitowski) and 16^th Infantry Division (commanded by Colonel Stanisław Świtalski) with both divisions being part of the larger, Pomorze Army.

Hostilities start

On 1 September 1939, German XXI Corps – commanded by General Nikolaus Von Falkenhorst – advanced on the area of Grudziądz with the 21st and 218th Infantry Divisions and started to push the Polish defenders back towards the east of the city, across the river Osa. The main German thrust focussed on the Polish left flank which was defended by the Polish 16^th Infantry Division. The German attack here faltered in the face of strong resistance but elsewhere the Germans managed to cross the Osa at Dąbrówka Królewska and establish a bridgehead.

After a brief pause for reinforcements, the Germans continued their advance and were only halted at 7 that evening. That night, the Poles launched a counterattack with the 4^th Infantry Division led by General Bołtuć and they quickly clashed with the German 218^th Infantry Division, managing to regain some of the ground they lost but ultimately grinding to a halt in the face of stiffening German resistance.

Second days fighting

Fighting continued the next day with an 8 am artillery barrage announcing the start of a fresh German assault, which was aiming to force the Polish 16^th Infantry Division to give up more ground. The Germans managed to expand their bridgehead and the Polish 64^th and 66^th Infantry Regiments (which were part of the 16^th Infantry Division) found themselves exposed and had to fall back towards the Grudziądz - Jabłonowo Pomorskie railroad.

In response, General Bortnowski sent in the 142^nd Squadron from the Polish Air Force (led by Colonel Boleslaw Stachoń) to attack the German positions, however the bombing failed to inflict any significant damage on the German forces so by the afternoon, the Polish troops began to fall back. The Germans, supported by fifth columnists, managed to cause panic during some Polish units whilst attacking the Polish 208 Reserve Infantry Regiment. (This apparent lack of discipline would lead to General Bołtuć dismissing Colonel Stanisław Świtalski, and replacing him with Colonel Zygmunt Bohusz-Szyszko.)

Polish machine gunners watching out for enemy aircraft.

https://ckziumragowo.pl/

Despite these setbacks, General Bołtuć ordered Colonel Lubicz-Niezabitowski's 4^th Infantry Division to launch a counterattack with the aim of taking the pressure of their compatriots in the 16^th Division which was facing increasing, relentless pressure from the Germans. The 4^th launched their assault from Radzyń Chełmiński at 8 in the evening, slamming into the German positions and forcing the enemy to retreat towards Annowo and Gruta. At the same time, the Polish 65th Infantry Regiment recaptured Nicwald. As before though, the Poles attack started to run out of steam before they could reach their original starting positions at Osa.  

Polish Withdrawal

German troops in Grudziądz

Wikipedia

The following day saw a massive German assault launched on the Polish positions as they sought to push the Poles back completely. General Bołtuć quickly learnt that his division on the western bank of the Vistula were being worn down by the German attacks and the enemy already crossed the river. In response, General Bołtuć withdrew his forces back to avoid being outflanked and encircled by the German forces.

The Poles destroyed bridges across the Vistula to hamper the German progress and pulled back towards the southeast and the Drwęca river, where a new defensive line was established.  This resulted in Grudziądz itself being abandoned that Sunday afternoon (3^rd Sept) by Polish forces and shortly afterwards, units from the German 45^th Infantry Regiment entered the city, with the complete capture of Grudziądz being completed by Monday 4^th September.

Polish prisoners marching into captivity after the battle.

http://ww2incolor.com

Further reading