What ended the religious unity of Western Europe?

The religious unity of Western Europe was ended by the Protestant Reformation, which began in the 16th century. The Reformation was a religious movement that led to the creation of new Protestant denominations and the split of the Catholic Church. The main cause of the Reformation was the desire for religious reform and the rejection of certain Catholic teachings and practices. The Protestant Reformation had a profound impact on Europe and led to religious conflicts, political upheaval, and the emergence of new religious identities and denominations.