On 31 October 1517, Martin Luther took a resolute stand that would ignite a sweeping transformation in European Christianity by sending his Ninety-five Theses to Albert of Brandenburg, the Archbishop of Mainz.
In his list of grievances, Luther vehemently criticised the Catholic Church's indulgence system, questioning its alignment with true Christian teachings and challenging the sale of salvation.
This act of defiance echoed throughout Christendom, inspiring a movement that would ultimately fracture the Church and set the foundation for the Protestant Reformation, reshaping religious thought and authority across Europe.