Ktož jsú boží bojovníci
The song was sung with such intensity during the Hussite Wars, that it instilled fear throughout the enemy army, making it a weapon in itself. One of the Imperial Crusades is believed to have fled the battlefield before the battle itself, just by hearing the Hussites singing proudly their hymn. The hymn would be led by a Hussite priest, who would be carrying a ceremonial axe. At the start of the 1433 war between the Polish and the Teutonic Knights of Prussia, the Hussites signed an alliance against the Germans in July 1433. In the course  of the war, they marched all the way to the Baltic sea at the town of Danzig. The Prussian 19th-century historian, Heinrich von Treitschke, makes a clearly indignant reference to the Hussite taking of land near the Baltic Sea and to "Kdož jsou Boží bojovníci" with these words: "greeted the sea with a wild Czech song about God's warriors and filled their water bottles with brine in token that the Baltic once more obeyed the Slavs." The song was used by Bedřich Smetana in his tone poems "Tábor" and "Blaník," and in a Czech march entitled "Slava chodsku  (Hail to the Chod Country!). It was also combined with a Catholic carol sung during the time of King Wenceslaus IV by Antonín Dvořák in his work "Husitská ouvertura" (Hussite Overture). Young composer Pavel Haas used it as material in his "Suite for Oboe and Piano" op. 12 (1939). Karel Husa also incorporated the tune in his "Music for Prague 1968", as did Karl Amadeus Hartmann in the "Concerto funebre" (1939, rev. 1959)."