Christianity originated in Palestine during the first century AD, rooted in the teachings of Jesus Christ, who was born in Bethlehem under Roman rule. Initially viewed as a threat to the Empire’s unity, Christians faced severe persecution, especially during the reign of Emperor Nero (AD 54–68). A significant turning point occurred in 312 AD when Emperor Constantine converted to Christianity, subsequently promoting it as the favored religion of the Roman Empire. The Edict of Milan in 313 AD granted religious toleration, allowing Christians to practice their faith openly, and by 392 AD, Christianity was established as the official religion under Emperor Theodosius the Great.

As Christianity flourished, it became a unifying force in Western Europe during the Middle Ages. Tensions between the Pope in Rome and the Bishop of Constantinople over authority and practices eventually led to the Great Schism in 1054, resulting in the separation of the Roman Catholic Church and the Greek Orthodox Church. This division was further complicated in the 16th century by the Protestant Reformation, which challenged Catholic practices and led to the emergence of various Protestant denominations. Today, these distinct branches of Christianity retain their identities, reflecting the diverse theological and cultural landscapes shaped by their historical developments.