The attack, known as the First Defenestration of Prague, took place on July 30, 1419, and is widely regarded as the event that ignited the Hussite Wars—a conflict that transformed medieval Bohemia and left a lasting mark on Czech history. Sign Up for our Newsletter Prague news, events, tips, food & moreHis execution outraged many across Bohemia. On July 30, radical Hussite preacher Jan Želivský led a religious procession through Prague after delivering an impassioned sermon. The defenestration did not, by itself, begin the Hussite Wars, but it made peaceful reconciliation increasingly unlikely. Just weeks later, King Wenceslas IV died, leaving the throne to his brother Sigismund, whom many Bohemians blamed for failing to protect Jan Hus at Constance.