How did Martin Luther start the Protestant Reformation?

Martin Luther challenged practices of the Catholic Church in 1517 by writing the Ninety-Five Theses, a list of arguments and grievances that called for debate and reform. He is traditionally said to have posted them on the church door in Wittenberg. He did not start the Reformation by printing a newspaper or distributing fliers during a service.

AI-written and checked against the verified answer.