The moment
Martin Luther, an Augustinian friar and professor at Wittenberg, challenged the sale of indulgences in his Ninety-five Theses. Rome excommunicated him in January 1521 and he refused to recant at the Diet of Worms, but printing spread his ideas and princes took them up. Zwingli meanwhile was reforming Zürich, and Geneva under Calvin later became the centre of the Reformed tradition.
People: Martin Luther, Philip Melanchthon