 On 31 October 1517, he enclosed in a protest letter to Albert of Brandenburg the Archbishop of Mainz, "The Ninety-five Theses" against the sale of indulgences and other Catholic practices, an action that marked the start of what came to be called the "Reformation".Although the Elector did not at first share the new attitude, he granted his protection to Luther anyway.Owing to this intervention, Pope Leo X decided against summoning Luther to Rome in 1518, and the Elector secured for Luther Imperial safe-conduct to the Diet of Worms in 1521.