Excerpts from Books and Wikipedia
"The confrontation between Holy Roman Emperor Charles V, only twenty-one years old but already aware of his responsibilities as the leading Catholic monarch of Europe, and Luther was inevitable once the reforming monk had taken the irrevocable step of burning the pope's bull of excommunication in December 1520. Luther was ordered to appear before the imperial diet (general assembly) at Worms to answer charges of heresy, under promise of safe conduct from the elector Frederick III of Saxony. . . . but there is some doubt as to whether he actually uttered the famous statement: 'Here I stand. I can do no other. God help me. Amen.' Charles V formally declared Luther an outlaw and ordered his arrest 'as a notorious heretic.' . . . Frederick of Saxony arranged that Luther should be seized and hidden, for his own protection, in his castle of Warburg at Eisenach. Luther remained there in secret for nearly a year, during which time he began the work of translating the New Testament into German so that the message of the Bible would be available to all." [Furtado: 1001 Days]