Martin Luther's advocacy for reforms in the early 16th century marked a pivotal moment in history known as the Protestant Reformation. In 1517, Luther famously posted his Ninety-Five Theses, critiquing the practices of the Catholic Church, particularly the sale of indulgences. His actions challenged the authority of the Pope and called for a return to biblical principles. Luther’s emphasis on faith and scripture led to the establishment of Lutheranism and encouraged other reformers to pursue religious changes. This grassroots movement fundamentally altered Christianity, led to the fragmentation of the Catholic Church, and ignited religious conflicts that would shape Europe for generations.