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The Battle of Kock, 1939: the last battle of the September Campaign

World War II · 2 to 6 October 1939 · Poland vs Germany · ~7 min read · Updated October 2026

Next anniversary: 2 October 2027, the 88th anniversary of the start 2 October in history ›

Dark locator map of Poland and the surrounding region with the Baltic coast, the Vistula and a gold star at Kock, east of the river, with a small world map inset.

Location map: © Echoes of Battle (data: Natural Earth, public domain).

At a glance

PolandGen. Franciszek Kleeberg (Independent Operational Group Polesie)
vs
GermanyGen. Gustav von Wietersheim (XIV Motorized Corps)
Date
2 to 6 October 1939
Location
Near Kock, eastern Poland
Period
German invasion of Poland (September Campaign)
Outcome
Polish tactical success; capitulation for lack of ammunition
By the numbers
SideStrengthLosses
PolandIndependent Operational Group Polesie: two improvised infantry divisions, the Zaza Cavalry Division and the Podlaska Cavalry Brigade, about 17,000 to 18,000 men with little artillery16,860 taken prisoner, including 1,255 officers and four generals
GermanyXIV Motorized Corps: the 13th Motorized Infantry Division, joined on 4 October by the 29thHeavy; no reliable figure

Strength from the Polish Army Museum (about 17,000) and Waldemar Kowalski (17,000 to 18,000); prisoner figures from Kowalski. No reliable count of the Polish dead is given in these sources.

Quick answer

Who won the Battle of Kock?

The Battle of Kock, fought from 2 to 5 October 1939 with the surrender on 6 October, was the last battle of the regular Polish army in the September Campaign. General Franciszek Kleeberg's Independent Operational Group Polesie, about 17,000 to 18,000 men gathered from reservists, retreating units and the Pińsk river flotilla, fought the German XIV Motorized Corps and forced its 13th Motorized Division back. With its ammunition gone, the group laid down its arms. Tactically the Poles won; the campaign itself had long been lost.1

On 18 September 1939 three Polish bombers took off from the airfield at Pińsk for Romania. The airfield's commander offered General Franciszek Kleeberg a seat. He refused. The war is lost, he said, but a soldier's honor is not; he had soldiers under his command and would not leave them. Eighteen days later, near the little town of Kock, those soldiers fought the last battle of the Polish campaign, and were still advancing when the bullets ran out.2

Three officers in uniform at a table covered with maps, one standing
Franciszek Kleeberg studying maps with the French General Louis Faury and Major Pillegand at the Higher Military School in Warsaw in 1926. Public domain

A group made from fragments

Franciszek Kleeberg, born in Tarnopol in 1888, had served in the Polish Legions, fought for Lwów in 1918 and 1919 and become a general in 1928. In 1939 he commanded the military district at Brest on the Bug. On 9 September, as German armies crossed the Narew at Wizna and swung toward Brest, the high command ordered him to form an Operational Group Polesie from reserve and rear units to hold the line from Brest to Pińsk.3

It was a heavy task with little to carry it. From 13 to 16 September, Kowalski writes, the garrison of the Brest fortress held off Heinz Guderian's XIX Panzer Corps. Along the way the group took in cavalry, artillery, dismounted sailors of the Pińsk river flotilla and soldiers of the Border Protection Corps.4

Dark locator map with a gold star in a glowing circle marking the approximate site of the Battle of Kock, the coasts, rivers and lakes of the region, and a small world map inset with the area boxed
The Battle of Kock: the star marks the approximate site, and the inset shows the area on a world map. Drawn for this article from Natural Earth data, with no modern borders. Location map: © Echoes of Battle (data: Natural Earth, public domain)

Between two invaders

On 17 September the Red Army invaded Poland from the east with nearly half a million men in its first wave. Caught between two powers, the Polish campaign was lost. The Commander in Chief, Marshal Edward Śmigły-Rydz, and the government crossed into Romania; Kleeberg stayed with his men.5› Soviet invasion of Poland, 1939

Kleeberg first planned to gather his forces at Kowel and fight his way to Romania, but the Soviets took Kowel first. On 22 September, learning that the Commander in Chief had left the country, he turned west to help besieged Warsaw, asking what the nation would say if the Polish army stopped resisting before it had exhausted every possibility. When Warsaw fell, he turned again: south toward the arms and ammunition depot at Stawy near Dęblin, and then into the Holy Cross Mountains to carry on the fight as partisans.6

He explained to General Zygmunt Podhorski that it was not a desperate decision but a political one. The war had to be prolonged, to show the world that Hitler had not conquered Poland in eighteen days as he boasted.7

The road to Kock

The march west was dogged by Soviet columns and armed bands. On 29 and 30 September the group beat Soviet units at Jabłoń and Milanów, and the group crossed the Bug near Włodawa. By 1 October its headquarters stood at Serokomla and its units held the country around Suków, Radzyń and Kock, a landscape of woods and bad roads that favored Polish infantry and horsemen over German trucks.8

The group was by then an army in miniature: the 60th Infantry Division, the 50th Infantry Division Brzoza, General Podhorski's Zaza Cavalry Division and the Podlaska Cavalry Brigade, with very little artillery and few antitank guns.9

Battle: 2 and 3 October

On 2 October Polish units ran into the German 13th Motorized Infantry Division, part of General Gustav von Wietersheim's XIV Motorized Corps. The German attack on the first day was beaten off, and the Poles went over to the offensive. Fighting spread across a wide area, around Kock, Serokomla, Krzywda, Wojcieszków, Adamów, Helenów and Wola Gułowska.10

How hard the Poles pressed shows in a German report of the evening of 3 October, quoted by the historian Waldemar Kowalski. It admitted that the corps and its 13th Motorized Division were fighting off with their main forces a Polish attack by all arms at and northwest of Kock, and that the fighting was not over.11

Two-story white classical palace with a green roof and a pediment, behind a formal garden with a round fountain basin
The Jabłonowski Palace in Kock, before which General Kleeberg surrendered to General von Wietersheim on 6 October 1939. Photograph of 2023. Bartek z Polski, CC0, via Wikimedia Commons

Battle: 4 and 5 October

On 4 October the Germans counterattacked, and the 29th Motorized Infantry Division under General Joachim Lemelsen came in from the northwest. Kleeberg sent part of his force against it and turned most of his units on the 13th Division. The heaviest fighting raged around Adamów, Krzywda and Wola Gułowska, which changed hands several times.12

On 5 October soldiers of the 60th Infantry Division and the cavalry struck the left wing of the 13th Motorized Division. In a daring attack they took the strongly held church and Carmelite monastery at Wola Gułowska and drove the Germans from the cemetery beside it. The German division was forced to fall back. It was a tactical victory.13

Veterans' memories of these days survive in recordings made for Radio Free Europe in 1969. Major Jerzy Mielżyński, who led a squadron of uhlans, recalled the last fight on 5 October in the forest by Wola Gułowska, where his men beat off three German attacks. A sergeant-major of the 1st Krechowce Uhlans remembered four days of fighting without a break, horses and men worn out, and an antitank gunner weeping as he loaded his last round.14

They were not beaten in the field. They simply ran out of bullets.

Out of ammunition

On the afternoon of 5 October the group's quartermaster reported to Kleeberg that the ammunition was gone, for the antitank guns and the rifles alike. Food and medicine for the wounded were also exhausted, and the group was the last Polish formation still fighting. In the forester's lodge at Hordzieszka, Kleeberg decided on his own responsibility to surrender.15

That evening he wrote his farewell order. He reminded his soldiers that he had gathered them from distant Polesie to fight to the end, that they had meant to help Warsaw and that Warsaw had fallen before they arrived. Now they were surrounded and further fighting would only waste blood that might still be needed. It is the privilege of a commander, he wrote, to take responsibility on himself. He thanked them for their courage and ended with the opening words of the national anthem: Poland is not yet lost.16

At eight that evening he told his officers. General Podhorski, who wanted to break through and fight on, did not attend. In the night the soldiers were paid, and some units buried their weapons so the Germans would not get them.17

The surrender

At eleven in the morning on 6 October, on an overcast day, Kleeberg surrendered to General von Wietersheim before the Jabłonowski Palace in Kock. Military honors were observed and the officers were allowed to keep their pistols. The sergeant-major of the 1st Krechowce Uhlans quoted above later remembered that the Germans saluted them as they marched into captivity.18

Into German captivity went 16,860 soldiers of the group, among them 1,255 officers and four generals: Kleeberg, Podhorski, Ludwik Kmicic-Skrzyński and Czesław Młot-Fijałkowski. The Germans took 10,200 small arms, 205 heavy machine guns, 20 guns and 5,000 horses; the rest had been destroyed or hidden.19

A bishop in mitre and vestments with his crozier passes officers in uniform, civilians and young people in caps kneeling by a wall with an iron gate
A field Mass at Radzymin in 1928 or 1929. Among those kneeling is General Franciszek Kleeberg, then commander of the 29th Infantry Division, ten years before he led the Polesie group at Kock. Public domain. Koncern Ilustrowany Kurier Codzienny archive, National Digital Archives of Poland (NAC 1-P-3538), via Wikimedia Commons.

Kleeberg and the memory of Kock

Kleeberg was held in the Oflag IV B prisoner camp in the fortress of Königstein in Saxony. Seriously ill with heart disease, he died in a military hospital at Weisser Hirsch near Dresden on 5 April 1941 and was buried in the Neustadt cemetery. In 1969, on the 30th anniversary of the battle, his remains were brought back to Poland and laid on 6 October in the war cemetery at Kock, among the soldiers who fell in the last battle of 1939. He was posthumously promoted to general of division.20

Kock closed five weeks of fighting in defense of Poland, which then lost its statehood for more than five years. It ended not in defeat in the field but with empty magazines, and it became a symbol of the soldiers of September who fought on after the campaign was lost. Many of them would fight again, in the underground and abroad.21

The campaign had opened at Westerplatte, and its largest battle was fought on the Bzura; see also the greatest battles in Polish history.

Frequently asked questions

When was the Battle of Kock?

The fighting lasted from 2 to 5 October 1939; the Polish soldiers laid down their arms on 6 October.

Who commanded the Poles at Kock?

General Franciszek Kleeberg, commander of the Independent Operational Group Polesie.

Who won the Battle of Kock?

The Poles had the upper hand and forced the German 13th Motorized Division back on 5 October, but ran out of ammunition and surrendered on 6 October.

Was Kock the last battle of the September Campaign?

Yes. It is regarded as the last battle of the regular Polish army in the 1939 campaign.

How many soldiers surrendered at Kock?

16,860, including 1,255 officers and four generals, according to Waldemar Kowalski; the Polish Army Museum gives about 17,000.

Why did Kleeberg fight on after Warsaw fell?

He wanted to reach the arms depot at Stawy near Dęblin and continue the fight from the Holy Cross Mountains, to show that Hitler had not conquered Poland in eighteen days.

What happened to General Kleeberg?

He was held at Königstein and died in German captivity in 1941. In 1969 his remains were reburied in the war cemetery at Kock.

Notes

A number in the text points to a note; each note names the works that paragraph draws on, listed in full under Sources.

  1. dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”; Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”. ↩
  2. dzieje.pl, “Bitwa pod Kockiem”; Polskie Radio, “Ostatnia bitwa Września”. ↩
  3. Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”; dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”. ↩
  4. dzieje.pl, “Bitwa pod Kockiem”. ↩
  5. dzieje.pl, “Bitwa pod Kockiem”; Alexandra Richie, “The Invasion of Poland”. ↩
  6. Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”; dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”. ↩
  7. dzieje.pl, “Bitwa pod Kockiem”. ↩
  8. dzieje.pl, “Bitwa pod Kockiem”. ↩
  9. Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”; Muzeum Wojska Polskiego, “5 października 1939 roku. Ostatni rozkaz gen. Franciszka Kleeberga”. ↩
  10. Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”; dzieje.pl, “Bitwa pod Kockiem”. ↩
  11. dzieje.pl, “Bitwa pod Kockiem”. ↩
  12. Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”; dzieje.pl, “Bitwa pod Kockiem”. ↩
  13. dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”. ↩
  14. Polskie Radio, “Ostatnia bitwa Września”; dzieje.pl, “Bitwa pod Kockiem”. ↩
  15. dzieje.pl, “Bitwa pod Kockiem”; Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”; Muzeum Wojska Polskiego, “Koniec bitwy pod Kockiem”. ↩
  16. dzieje.pl, “Bitwa pod Kockiem”; Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”; Muzeum Wojska Polskiego, “5 października 1939 roku. Ostatni rozkaz gen. Franciszka Kleeberga”. ↩
  17. dzieje.pl, “Bitwa pod Kockiem”. ↩
  18. dzieje.pl, “Bitwa pod Kockiem”; Polskie Radio, “Ostatnia bitwa Września”. ↩
  19. dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “5 października 1939 roku. Ostatni rozkaz gen. Franciszka Kleeberga”. ↩
  20. Instytut Pamięci Narodowej, “Generał Franciszek Kleeberg”; dzieje.pl, “Bitwa pod Kockiem”. ↩
  21. dzieje.pl, “Bitwa pod Kockiem”; Muzeum Wojska Polskiego, “5 października 1939 roku. Ostatni rozkaz gen. Franciszka Kleeberga”. ↩

Sources

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