Excommunication

In 1518, the Roman Catholic Church brought Martin Luther up on charges of heresy. The hearing was planned to take place in Rome, but Frederick the Wise, the Elector of Saxony, insisted it be moved to Augsburg. Here, the papal legate, Cardinal Cajetan, pushed Luther to retract his statements. Luther refused and was forced to flee the city.
In 1519, Luther defended his beliefs against Johann Eck at the Leipzig Debate. He argued that even church councils were fallible and cast doubt on the divine authority of the papacy, controversial statements that led his detractors to brand him a heretic.

On June 1, 1520, the Pope issued a bull threatening Martin Luther with excommunication. On December 10 of the same year, Luther set this bull on fire in front of one of the Wittenberg town gates to cheers from the watching crowd. At this point, Luther's writings were the most frequently printed works in the Holy Roman Empire.