John Zizka (zĬs´kə), Czech Jan Žižka (yän zhēsh´kä), d. 1424, Bohemian military leader and head of the Hussite forces during the anti-Hussite crusades of Holy Roman Emperor Sigismund. Before the Hussite Wars, which gave his military genius the opportunity to develop fully, Zizka served under various lords; he fought (1410) on the Polish side in the battle of Tannenberg, in which the Teutonic Knights were defeated. When the Hussite Wars broke out in 1420, Zizka was about 60 years old and blind in one eye. Having joined the Taborites (the radical Hussite wing), Zizka made Tábor in Bohemia into an almost impregnable fortress and led (July, 1420) the Taborite troops in their victory over Sigismund at Visehrad (now a part of Prague). In the following years he successfully withstood the anti-Hussite crusades and took one Catholic stronghold after another, continuing to command in person although he had become totally blind in 1421. He did not agree with the extreme religious views of the Taborites, and in 1423 formed his own Hussite wing, which, however, remained in close alliance with the Taborites. In the same year the tension between the Taborites and the moderate Utraquists, whose stronghold was at Prague, flared into open conflict, and late in 1424, Zizka led his army against Prague in order to compel that city to adhere to his uncompromising anti-Catholic policy. An armistice averted the outbreak of civil war between the two Hussite parties, which then decided on a joint expedition into Moravia under Zizka's command. Zizka died suddenly during the campaign. Although Zizka's fame is overshadowed by that of other commanders, he ranks with the great military innovators of all time. The bulk of his army consisted of peasants and townspeople, untrained in arms. Zizka did not attempt to make them adopt the conventional armament and tactics of the time, but let them make use of such weapons as iron-tipped flails and armored farm wagons, surmounted by small cannons of the howitzer type. His armored wagons, when used for offense, easily broke through the enemy lines, firing as they went, and thus enabled him to cut superior forces into pieces. When used for defense, the wagons were arranged into an impregnable barrier surrounding the foot soldiers; they also served to transport his men. Zizka thus fully anticipated the principles of tank warfare.