The development of large cavalry formations was based on two main reasons. First of all, Poland was not economically ready and lacked the production capacities to form and maintain armored forces comparable to the German or French ones. Secondly the tradition of the Polish cavalry was still very significant and played huge role in the Army. Those forces were well trained and adapted to Polish conditions. Cavalry, during the 1939, fought both mounted and on foot, depending on the situation. Most of the time horses were use as a transport, to quicky change positions and surprise the enemy, but in some of the cases unconventional approach was needed.
Due to defensive character of September Campaign cavalry units often fought as regular infantry, holding fortified positions. Cavalry Brigade, called „Mazowiecka” („Mazovian”), fighting alongside with several infantry formations held back Germans in the course of battle of Mława. For over 4 days Polish cavalry and infantryman stood their ground, despite being outnumbered and outgunned.