Short answers, pulled from the story.
Martin Luther nailed the Ninety-five Theses to the door of the Castle Church in Wittenberg on the 31st of October 1517. This document challenged the authority of the Pope and the sale of indulgences. The act ignited a firestorm across Europe and transformed a local academic dispute into a continental crisis.
Philipp Melanchthon was a young professor of Greek at Wittenberg known as the Praeceptor Germaniae or Teacher of Germany. He systematized the teachings of Martin Luther and produced the Augsburg Confession in 1530. Melanchthon established schools and universities to train a new generation of pastors and leaders.
Huldrych Zwingli was a priest and scholar in Zurich who focused on the authority of scripture alone and rejected traditions not proven by the Bible. He engaged in fierce debates with Luther over the nature of the Eucharist and failed to find common ground. Zwingli died in battle at the 1531 Battle of Kappel, marking a turning point in the Reformation.
John Calvin established a theocratic government in Geneva and wrote the Institutes of the Christian Religion as a comprehensive guide to Protestant belief. He corresponded with reformers in Scotland, England, and the Netherlands to shape the direction of the Reformation. Calvin founded the Academy of Geneva to train pastors and leaders who would carry the movement across Europe.
Thomas Cranmer served as the Archbishop of Canterbury and oversaw the translation of the Bible into English. He wrote the Book of Common Prayer which standardized worship in English and became a cornerstone of Anglican identity. Cranmer was burned at the stake for his faith in 1556 after being forced to recant his Protestant beliefs under Queen Mary I.
The Council of Trent convened in 1545 to clarify Catholic teachings on salvation, the sacraments, and the authority of the church. It implemented reforms to improve the education and discipline of the clergy and established new religious orders like the Society of Jesus. This Counter-Reformation helped stabilize the Catholic Church and prevent the complete collapse of its authority in Europe.