Who was a significant reformer that challenged the corruption of the Roman Catholic Church in the 16th century?

Martin Luther was a significant reformer who challenged the corruption of the Roman Catholic Church during the 16th century, a period marked by the beginning of the Protestant Reformation. He is best known for his Ninety-Five Theses, which criticized the sale of indulgences and questioned the authority of the church. Luther's actions sparked widespread religious reform and led to the establishment of various Protestant denominations, fundamentally altering the religious landscape of Europe.

His emphasis on faith and scripture as the foundations of Christian belief, rather than the traditions upheld by the church, resonated with many who were disillusioned with the perceived moral decay and financial corruption of the clergy. Luther's reform movement encouraged individuals to seek a personal relationship with God, challenging the centralized authority of the Catholic Church and ultimately contributing to significant changes in religious practices and beliefs across Europe.