Martin Luther is recognized for starting the Reformation with his Ninety-Five Theses, which he posted on the door of the Castle Church in Wittenberg in 1517. This document criticized the Catholic Church's practices, particularly the sale of indulgences, and called for reform. Luther's theses sparked a widespread theological debate and led to the establishment of various Protestant denominations. His actions are often viewed as a significant catalyst for a movement that challenged the authority of the Catholic Church and promoted the idea of personal faith, scripture interpretation, and the priesthood of all believers. This movement ultimately reshaped the religious landscape of Europe.