Martin Luther was summoned to the diet in order to renounce or reaffirm his views in response to a Papal bull of Pope Leo X.
At the end of the diet, the Emperor issued the Edict of Worms (Wormser Edikt), a decree which condemned Luther as "a notorious heretic" and banned citizens of the Empire from propagating his ideas.
In June 1520, Pope Leo X issued the Papal bull Exsurge Domine ("Arise, O Lord"), outlining 41 purported errors found in Martin Luther's Ninety-five Theses and other writings related to or written by him.
Luther continued to preach, write, and publish his attacks on the Church, was excommunicated in January 1521, and told to appear before the assembly at the city of Worms (pronounced Verms).
Frederick III, Elector of Saxony obtained an agreement that, if Luther appeared, he would be promised safe passage to and from the meeting.
[5] This guarantee was essential after the treatment of Jan Hus, who was tried and executed at the Council of Constance in 1415 despite a promise of safe conduct.
[9] Pappenheim reminded Luther that he should speak only in answer to direct questions from the presiding officer, Johann von Eck [de].
It was a fitting respite for one whom the Nuremberg Mastersinger Hans Sachs called “the Wittenberg nightingale.”[15] The Edict of Worms was a decree issued on 25 May 1521 by Emperor Charles V.[16] Its contents proscribed Luther's writings, declaring him a heretic and an enemy of the state, even permitting anyone to kill Luther without legal consequence; the imperial ban.
[17] It was the culmination of an ongoing struggle between Martin Luther and the Catholic Church over reform, especially concerning the practice of donations for indulgences.
However, there were other deeper issues that revolved around both theological concerns: The Diet of Worms was also the occasion for Charles V to reform the administration of the Empire.
Given the vast domains of the House of Habsburg, the Emperor was often on the road and needed deputies, including the Governors of the Netherlands and the Regents of Spain, for the times he was absent from his territories.
As such, Ferdinand became regent and governor of the Austrian hereditary lands of Charles V and the Emperor's representative in Germany.
In December 1521, Jacob Proost, prior of the Augustinian monastery in Antwerp, was the first Luther-supporting cleric to be arrested and prosecuted under the terms of the Worms Edict.
Two monks, Jan van Essen and Hendrik Vos, refused to recant; on 1 July 1523, they were burned at the stake in Brussels.