Protestant Reformers were theologians whose careers, works and actions brought about the Protestant Reformation of the 16th century. In the context of the Reformation, Martin Luther was the first reformer, sharing his views publicly in 1517, followed by Andreas Karlstadt and Philip Melanchthon at Wittenberg, who promptly joined the new movement. In 1519, Huldrych Zwingli became the first reformer to express a form of the Reformed tradition. Listed are the most influential reformers only. They are listed by movement, although some reformers influenced multiple movements and are included in each respective section. Proto-Protestantism Throughout the Middle Ages, according to Edmund Hamer Broadbent, there were a number of Christian movements that sought a return to what they perceived as the purity of the Apostolic church and whose teachings foreshadowed Protestant ideas. Claudius of Turin Gottschalk of Orbais Berengar of Tours Peter Waldo Lorenzo Valla Wessel Gansfort Girolamo Savonarola Jacques Lefèvre d'Étaples John Wycliffe Jan Hus There were a number of key reformers within the Magisterial Reformation, including: Martin Luther Philipp Melanchthon Justus Jonas Martin Chemnitz Georg Spalatin Joachim Westphal Andreas Osiander Johannes Brenz Johannes Bugenhagen Andreas Karlstadt, later a Radical Reformer Hans Tausen Mikael Agricola Primož Trubar Jiří Třanovský Huldrych Zwingli Martin Bucer John Calvin Heinrich Bullinger Theodore Beza William Farel John Knox Wolfgang Capito Johannes Oecolampadius Peter Martyr Vermigli Leo Jud Thomas Cranmer Thomas Cromwell Matthew Parker William Tyndale Hugh Latimer Richard Hooker Jacobus Arminius Ferenc Dávid Important reformers of the Radical Reformation included: Thomas Müntzer Zwickau prophets John of Leiden Menno Simons Dirk Willems Kaspar Schwenkfeld There were also a number of people who initially cooperated with the Radical Reformers, but separated from them to form a "Second Front", principally in objection to sacralism. Among these were: Johannes Bünderlin Hans Denck Chris