Luther was kidnapped to protect himself
Luther quickly became a thorn in the side of the papacy. On June 15, 1520, Pope Leo X announced a public decree warning Martin Luther that if he did not retract 41 sentences from his works within 60 days, he would be excommunicated. Instead, on December 10, Luther officially set fire to the order. On January 3, 1521, the Pope excommunicated Luther.
Then, on April 18, Luther was invited to Worms, Germany to attend the Diet, a large assembly of the Holy Roman Empire. He was asked to renounce his writings once more during the Diet of Worms. He emphasized, however, that he would be influenced only by reason or if it was written otherwise in the holy scriptures. He finished his testimony with a strong statement: “Here I stand. God help me. I can do no other.”
Holy Roman Emperor Charles V instantly declared him a heretic and an outlaw. His arrest was ordered, his books were prohibited, it became unlawful to shelter him, and killing him in broad daylight would result in no consequences.
Understanding how tense the situation was, Luther's protector, Frederick the Wise, decided that he needed to remain hidden until the Church's passions calmed. As a result, he directed a group of knights to "kidnap" Luther, who was subsequently brought to a castle in Eisenach. For almost a year, Luther lived in a disguise as a nobleman named "Junker Jörg".