The phrase Diet of Worms comes from the word Diet, which is from the Latin "dies" meaning "day" and Worms, which is the name of the place the meeting was held.

With Emperor Charles V presiding, it took place in Worms, Germany, a small town on the Rhine river, from January 28 to May 25, 1521. Although other issues were dealt with at the Diet of Worms, it is most memorable for addressing Martin Luther and the effects on the Protestant Reformation.

The previous year, Pope Leo X had issued the Papal bull Exsurge Domine, demanding that Luther retract 41 of his 95 theses criticising the Church. Luther was summoned by the Emperor to appear before the Imperial Diet. Prince Frederick III, Elector of Saxony obtained an agreement that if Luther appeared he would be promised safe passage to and from the meeting. Such a guarantee was essential after the treatment of Jan Hus, tried and executed at the Council of Constance in 1415, despite a safe conduct pass.

Standing before the assembled Diet, Luther made a number of statements in his defence that were to become famous. He admitted to the authorship of the literature bearing his name, but refused to withdraw his teachings. He argued that he could not recant unless he became convinced to do so sola scriptura ("from Scripture alone"). Luther argued,

"Unless I am convinced by the testimony from scripture or by evident reason – for I confide neither in the Pope nor in a Council alone, since it is certain they have often erred and contradicted themselves – I am held fast by the scriptures adduced by me, and my conscience is held captive by God’s Word, and I neither can nor will revoke anything, seeing it is not safe or right to act against conscience. God help me. Amen."

This argument struck to the heart of the Church's teachings on Authority versus Scripture.

The Papal nuncio at the Diet, Girolamo Aleandro, drew up and proposed the fierce denunciations of Luther that were embodied in the Edict of Worms, promulgated on May 25. These declared Luther to be an outlaw and banned the reading or possession of his writings, a divisive move that distressed more moderate men, and in particular Erasmus.

Despite the agreement that he could return home safely, it was privately understood that Luther would soon be arrested and punished. To protect him from this fate, Prince Frederick seized him on his way home and hid him away in Wartburg Castle. It was during his time in Wartburg that Luther began his German translation of the Bible.

The Edict Of Worms

The Edict of Worms was issued by Charles V, Holy Roman Emperor on May 25, 1521 at Worms, at the end of the Diet of Worms. It contained a condemnation of Martin Luther and declared him to be an outlaw and a heretic for his opposition to the doctrines of the Roman Catholic Church. Among other things, this ruling permitted anyone to kill Luther without suffering legal consequence, and the property of Luther's followers and supporters could be seized by force. Luther was in fact granted free passage across the Holy Roman Empire and thus returned to Wittenberg where he was protected by the Elector Friedrich until 1522 when he felt compelled to return from his exile there to defend his views in the context of the revolution they had caused.

When Luther eventually came out of hiding, the Emperor was preoccupied with military concerns, and because of rising public support for Luther among the German people, the Edict of Worms was never enforced. Luther continued to call for reform until his death in 1546.