ENThe financial malfunction of the Commonwealth caused severe problems in paying the military troops during the protracted war with Moscow (1609– –1618), which followed immediately after the lengthy and costly Livonian War. The crisis was deepened by the formation of military confederations, which terrorised the country and forced the acceptance of excessive wage claims. Therefore, both the Polish authorities and the commanders of individual units sought additional sources of income, e.g. in Ducal Prussia. King Sigismund III managed to obtain at least 420 thousand zlotys from Prussia by treaty. At the same time, Polish and Lithuanian commanders forced the Prussians to pay the equivalent of more than 100 thousand zlotys. Aid from Prussia was obtained in the form of military stations, paid for in money or food supplies. The methods of negotiating the stations and the financial consequences for both the Polish-Lithuanian army and Ducal Prussia have been discussed based on the archival correspondence of military commanders and Prussian authorities. Keywords: Ducal Prussia, army, finances. [From the publication]