Martin Luther's nailing of his 95 Theses to the church door in Wittenberg in 1517 is seen as sparking the Protestant Reformation. The document outlines several issues with the Catholic Church that paved the way for reform, including corruption such as the selling of indulgences, as well as political conflicts between popes and kings that undermined the Church's authority. Luther's spreading of his teachings through writings helped grow the new Protestant movement against Catholic doctrine and power of the papacy. The Reformation transformed Christianity in Europe.