Prussian Army (Polish Armed Forces)

The army, divided into two groups, northern and southern, was concentrated southwest of Warsaw (in the triangle between Kielce, Radom, and Tomaszów Mazowiecki), as Marshall Edward Śmigły-Rydz was convinced that main German thrust would be directed at Warsaw, via Łódź.

This miscalculation led to the capture of the city of Łódź - a major setback to the Polish plan of defending the country west from the Vistula river at least until October 1939.

The report was prepared by the Polish generals and handed to the French, and the British in their respective languages, in late 1939.

Because of fast German advance both groups entered combat separately and most units did not reach full mobilization.

Due to the deteriorating situation in the battle of the border, it was decided to push partially mobilized units of Prusy Army to the front as soon as possible.

In original Polish plans, the 10th Motorized Cavalry Brigade belonged to the Prusy Army.

The southern group, much less organized and poorly commanded, fought in the Battle of Iłża, after which it was cut off from the Vistula, encircled near Radom and destroyed (September 8–9).