Firearms were first used in the field as provisional last resort together with wagon fort. Significantly outnumbered Hussite militia led by Jan Žižka repulsed surprise assaults by heavy cavalry during Battle of Nekmíř in December 1419 and Battle of Sudoměř in March 1420. In these battles, Žižka employed transport carriages as wagon fort to stop enemy's cavalry charge. Main weight of fighting rested on militiamen armed with cold weapons, however firearms shooting from behind the safety of the wagon fort proved to be very effective. Following this experience, Žižka ordered mass manufacturing of war wagons according to a universal template as well as manufacturing of new types of firearms that would be more suitable for use in the open battlefield.