To what extent did Luther's challenge to the church change in the years 1517-21?

-I'm pants at researching but need the answer soon before I have to sit a mock-exam.

Can anyone list out any key features and/or dates?Luther went from seeking to reform the Church and its corrupt practices to challenging the legitimacy of Papal authority.



See



http://en.wikipedia.org/wiki/Martin_Luth鈥?/a>