Bohemia was thoroughly prepared by the labors of John Hus and Jerome of Prague, who were burned at the stake as heretics by order of the Council of Constance (the one July 6, 1415, the other May 30, 1416), but left a large number of followers, especially in the Czech or Slavic portion of the population. The wars which followed would have resulted in the triumph of the Hussites, if they had not been broken up by internal dissensions From their remnants arose the "Unitas Fratrum," or the "Bohemian Brethren." They endeavored to reproduce the simplicity and purity of the apostolic church, and were in fraternal alliance with the Waldenses. Notwithstanding their violent persecution, they perpetuated themselves in Bohemia and Moravia. When the Reformation broke out, they sent several deputations to Luther; and many of them embraced the doctrines of the Augsburg Confession, but the majority passed to the Reformed or Calvinistic communion. During the reign of Maximilian II, there was a fair prospect of the conversion of the whole Bohemian nation; but the bloody Thirty Years' War (which began in Prague, 1618), and the counter-Reformation of the Jesuits, crushed Protestantism, and turned Bohemia into a wilderness. A Jesuit named Anton Koniasch (1637) boasted that he had burned over sixty thousand Bohemian books, mostly Bibles. The Bohemian Brethren who had fled to Moravia became, under Count Zinzendorf's care, the nucleus of the Moravian Church (1722), which continues to this day one of the smallest but most active, devoted, and useful among evangelical denominations. But even in Bohemia Protestantism could not be utterly annihilated, and began to raise its feeble head when the emperor, Joseph II., issued the famous Edict of Toleration, Oct. 29, 1781. The recent revival of Czech patriotism and literature came to its aid. The fifth centenary of Hus was celebrated in Prague, 1869, and his works and letters were published. In 1880 there were about fifty Reformed congregations in Bohemia, and thirty in Moravia, holding to the Second Helvetic Confession and the Heidelberg Catechism. The number of Lutheran congregations is smaller, and mostly confined to the German part of the population.