Martin Luther is credited with beginning the Protestant Reformation but with what actions?

Martin Luther initiated the Protestant Reformation in 1517 by posting his Ninety-Five Theses on the door of the Wittenberg Castle Church. This document criticized the Catholic Church's sale of indulgences and called for reforms in church practices and doctrines. His actions sparked widespread debate and led to the establishment of various Protestant denominations, fundamentally challenging the authority of the Catholic Church. Luther's emphasis on scripture and faith as the basis for salvation reshaped Christian theology and practice.