Preparing the defences

Placement of German and Polish units in September 1939.

Halibutt Wikipedia

In 1939, with tensions growing increasingly worse between Germany and Poland, General Emil Krukowicz-Przedrzymirski, commander of the Polish “Modlin” Army, was directed to defend the Polish northern border, as part of the plan formulated a plan to counter any German aggression.

The border lay next to East Prussia and defence of this region was vital due to the belief that if invading German forces breached the defences, they would target the Polish Capital, Warsaw.

In the lead up to hostilities breaking out, the Poles strengthened the defences in the area, building fortification and reinforced concrete shelters, much of it centred around, or close to, the town of Mlawa.

General Emil Krukowicz-Przedrzymirski

Map of Poland in 1939 with location of the battle marked with an X.

The commander of the Modlin army elected to try and conduct any defence as far north as possible, ignoring the natural defence lines of the Narew, Bug and Vistula rivers, and instead planning to confront any German invader directly on the border with East Prussia – the Lidzbark – MławaKrzynowłogi line. Essentially, he planned to repel the Germans before they gained any sort of foothold on Polish soil.

The main Polish forces allocated to conduct this defence was the 20th Infantry Division with the left flank of the division being shielded by the Novogrod Cavalry Brigade and the right being defended by the Mazovian Cavalry Brigade, Additionally, elements of the 8th Infantry Division were stationed at Ciechanów and called upon if needed.

Outbreak of war

With the outbreak of war on 1 September 1939, the Mazovian Cavalry Brigade, commanded by Colonel Jan Karcz, who found themselves under attack by the German 12th Infantry Division, led by Lieutenant General Ludwig von Leyen.

Part of the Mazovian Cavalry Brigade, the 11th Regiment of Legionary Uhlans, found themselves fighting in the area of Chorzel and Krzynowłoga Mała, as they sought to protecting the flank of the 20th Infantry Division – commanded by Colonel and  Liszka-Lawicz – to prevent German forces circling around behind them and attacking from the rear.

Colonel Jan Karcz, commander of the Mazovian Cavalry Brigade.

The Poles had a mixture of units in which to conduct the defence, organised into battle groups and detachments. They had a variety of troops, artillery pieces spread out amongst them, a company of sappers and a platoon of cyclists, and they focussed their defence on covering key points in this are – for example, the road junction in Krzynowłoga Mała, to block off German attempts to manoeuvre around them.

Fighting starts

It wasn’t long before the German 12th Infantry Division and units from the German 1st Cavalry Brigade (commanded by Colonel Kurt Feldt) clashed with the Polish defenders. The 2nd and 4th Cavalry squadrons – led by Lieutenant Adam Szulczewski and Franciszek Wrzosek – managed to hold off the German attackers for four hours, before conducting an orderly withdrawal to a new defensive position, helped by accurate supporting fire from 1 battery of the 1st Horse Artillery Squadron.

In Rembielin, the Polish 1st Cavalry Squadron held of the advancing Germans for an hour and a half, supported by accurate fire from the Uhlans No.1 anti-tank battery which destroyed several German vehicles and hampering their progress.

11th Legionary Uhlan Regiment during peacetime.

In the village of Zembrzus-Mokry Grunt, a few kilometres from Janów, a patrol from the Polish 4th squadron of the 11th Infantry Division, led by Lieutenant Władysław Kossakowski, clashed with German forces which were already in the village in strength. Heavy machine gun fire from the Germans – which included a patrol of motorcyclists – forced the Poles to withdraw to the nearby forest.

Throughout the rest of the day, skirmishes continued between the two sides, including a clash with German cavalry – a rare example of a cavalry v cavalry skirmish in this war – which fittingly took place in a location known as the Royal Forests.

The commander of the patrol, Lieutenant Kossakowski, described the cavalry exchange in vivid detail:

Several men were killed and wounded on both sides, with the Poles also capturing a prisoner. That evening, Kossakowski led his cavalry off the battlefield, transporting a seriously wounded Uhlan - Dydach Błaszkiewicz – with them.  The Polish units could feel pleased – they had successfully hampered and delayed the German advances.

German cavalry unit (photographed on the Eastern Front, 1941).


The Germans had failed to break through the defensive line in this area, although their main effort was directed towards Mlawa. The Poles had taken a few dozen killed and wounded, with the Germans probably suffering similar losses.

The Poles also lost an artillery piece, and three vehicles were destroyed with the Germans losing about a dozen of their own vehicles. The next day, the Poles pulled back to a new defensive line stretching across the villages of Rudno Jeziorowe, Łoje, Łanięty and Drążdżewo.