The martydom of Hus
In 1346, Charles IV, upon becoming Emperor of the “Holy Roman Empire”, made the Bohemian city of Prague the imperial capital. Charles founded a great university in Prague. Through the university, clerics in Prague learned of the reformist ideas of John Wyclif, the professor and theologian of Oxford University.
One cleric influenced by Wyclif was Jan Hus (or John Huss). Hus was confessor to Queen Sophia, wife of Wenceslas IV, son and sucessor to Charles IV. Hus thus initially was supported by the king and the local reformist clergy, including the archbishop. However, Hus attacked the activities of papal envoys selling indulgences to fund the crusade against the King of Naples. Riots broke out, sales of indulgences dried up, and Hus was excommunicated in 1411. He lost the support of the archbishop and the Emperor and was forced to flee Prague
In 1414, King Sigismund of Germany (Wenceslaus’ brother) called a general council to resolve the problem of the “Great Schism” (the college of cardinals had elected three different popes). The Council of Constance was also expected to deal with the issue of reform and end the controversy over the Wycliffite movement. Sigismund promised safe passage to Hus. In Constance, however, Hus was seized and thrown in a dungeon. Hus refused to recant his Wycliffite reformist ideas. He was condemned as a heretic, and handed over to the secular authority, Sigismund, who ordered him burned at the stake on July 6, 1415.
Czechs Adopt Religious Reforms
News of Jan Hus' death at the stake in July of 1415 enraged the population in Bohemia and Moravia. Ethnic Czechs declared that the way Hus was treated was an insult to the whole country. The Czech nationalists challenged papal authority, and adopted a new symbol of their movement, the chalice. Over the centuries, the Church had gradually abandoned the practice of serving both wine and bread to the people at Mass, giving the people only bread and reserving the wine for the clergy. The reformers insisted Communion in Both Kinds(sub ultrque species), wine as well as bread. They were called the Ultraquists or the Chalists. In Prague, communion was given in both kinds, and the Mass was celebrated in Czech instead of Latin, at Hussite churches. For awhile, Catholic and Hussite churches co-existed in Prague, divided along ethnic lines: Germans in the Catholic churches and Czechs in the Hussite churches.
The First Defenestrations of Prague and the Hussite Wars
In 1419, under Roman Catholic pressure, Wenceslas allocated only three Prague churches to the Hussites. A Hussite mob stormed the council chambers of City Hall, and two Catholic councilmen were defenestrated, i.e. thrown out the window to their deaths. Wenceslas died shortly after this event, known as the First Defenestration of Prague.
Sigismund succeeded Wenceslas as Holy Roman Emperor and King of Bohemia, but as the man who had ordered Jan Hus burnt at the stake, he was vilified by the Czechs. Pope Martin V, just elected by the Council of Constance, declared a crusade against Bohemia. Sigismund obligingly raised an army and advanced toward Prague. Hus' followers organized. John Zizka was chosen general. Between 1420-1430, Zizka's forces, employing the most modern tactics and weapons, crushed six (6) German crusades against the Hussites. Hussite military victories secured Czech independence for the next 200 years.
Epilogue: the Reformation, the Thirty Years War and End of Czech independence
Slightly over 100 years after Hus was burned at the stake, an Augustinian professor, Martin Luther, announced a academic debate by posting debating points (“the 95 Theses”) including Hussite denunciations of indulgences, in the manner debates were announced at Wittenberg University: by nailing the announcement on the cathedral doors. Czech Protestant independence lasted until the pan-European religious slaughter known as the Thirty Years' War. During the Thirty Years War (which began with the Second Defenestrations of Prague) Czech Protestant forces were defeated by Catholics. The Peace of Westphalia in 1648 handed Eastern Europe over to the Catholic Habsburgs.
Hussites in Battle (contemporary illustration): http://www.hedgehog-review.com/ttt/HusII.html
Images (of what, I’m not sure precisely, I don’t speak Czech, but it appears to be Hussite stuff and portraits):