The Protestant Reformation This sixteenth-century painting by the well-known German artist Lucas Cranach the Elder shows Martin Luther and his supporters using a giant quill to write their demands for religious reform on a church door. It memorializes the posting of the Ninety-five Theses in 1517, which launched the Protestant Reformation. (Dr. Henning/Schliefenbaum, Sieger, Germany/Visual Connection Archive)