The most active supporters of the uprising were the citizens of Prague, as well as the nobles who belonged to the community of Czech Brothers. A direct reason for the Prague uprising of the Estates was the attempt of Ferdinand I to provide military and financial support to his brother Emperor Charles V in his war with the Protestant Schmalkaldic League of German principalities. In December 1546, King Ferdinand I tried to obtain the consent of the General Sejm to allocate funds to finance the imperial troops, but received a categorical refusal [4]. The estates and a large part of the nobility of Bohemia had denied him support in the German campaign.