Definition
Martin Luther (1483 to 1546) was a German monk, priest, and professor of theology whose protest against Church practices triggered the Protestant Reformation. In 1517 he wrote his 95 Theses, a list of objections to the Church's sale of indulgences — payments said to reduce punishment for sin.
Luther had not set out to break with Rome. He intended to spark debate. But his arguments, amplified by the printing press, spread across Europe within weeks and grew into a movement he could no longer contain or control.
Why it matters
How it works
Luther's influence rested on three things: a clear theological argument, a powerful new medium, and political cover. His ideas were simple enough to grasp and radical enough to matter. Printed pamphlets and his vernacular Bible carried them to a mass audience that could now read the case directly.
When the Church and the Holy Roman Emperor demanded he recant, Luther refused. German princes who resented Rome's power and wealth shielded him, turning a religious dispute into a lasting political and institutional rupture.