The Hussite Wars (1419-1436) followed the burning at the stake of Jan Hus in 1415 which aroused enormous religious and national unrest inBohemia, and led to the formation of the Hussite League. The movement spread rapidly under King Wenceslas IV and open war broke out under Sigismund, whom the Bohemians held responsible for Hus's death. In 1420 the pope called for a crusade against the Hussites. The Emperor suffered serious defeats, and raids into Silesia, Austria and as far as Gdańsk spread fear of the Hussites. For the first time, an imperial tax was levied to fund the war against them. Continued Hussite successes led to a diplomatic solution being reached in the pacts of Prague (1433) and Iglau (1436).