On the last day of October 1517, Martin Luther famously nailed his 95 Theses to the doors of the Castle Church of Wittenberg. Upset over the sale of "indulgences" and other priestly fundraising behaviors, Luther started:
Out of love for the truth and the desire to bring it to light, the following propositions will be discussed at Wittenberg, under the presidency of the Reverend Father Martin Luther, Master of Arts and of Sacred Theology, and Lecturer in Ordinary on the same at that place. Wherefore he requests that those who are unable to be present and debate orally with us, may do so by letter.
The 95 Theses can be found here. Cliff notes on the story are here.