Infantry was the most numerous and one of the most important formations in the Polish armed forces in the interwar period and during the September campaign. During the September campaign of 1939, the basic operational unit of the Polish infantry - as in almost every European army of that time - was a division, which, after mobilization, was to reach approx. 16,500 soldiers. Its basic strike force was three infantry regiments, supported by anti-aircraft and anti-tank artillery (27 37 mm cannons in full time) and light and heavy artillery (24 or 12 75 mm cannons in full time, 12 or 24 100 mm cannons, 3 105 mm cannons and 3 howitzers 155 mm). It is worth adding that the Polish infantry division showed many shortcomings compared to the German division. First of all, it had fewer machine guns and, above all, light and heavy artillery. Moreover, in the case of the Wehrmacht, the latter were significantly better equipped with motor vehicles, which improved their mobility and had much better means of communication and communication. For example: the German infantry division had 938 full-time cars, while the Polish - only 76 motor vehicles! This translated into the effectiveness of both formations on the battlefield, as well as their firepower and mobility.