The history of Christianity follows the Christian religion from the first century to the twenty-first as it developed from its earliest beliefs and practices, spread geographically, and changed into its contemporary global forms. Christianity originated with the ministry of Jesus, a Jewish teacher and healer who proclaimed the imminent Kingdom of God and was crucified c. AD 30–33 in Jerusalem in the Roman province of Judea. The earliest followers of Jesus were apocalyptic Jewish Christians. Christianity remained a Jewish sect, for centuries in some locations, diverging gradually from Judaism over doctrinal, social and historical differences. In spite of occasional persecution in the Roman Empire, the religious movement spread as a grassroots movement that became established by the third century both in and outside the empire. The Roman Emperor Constantine I became the first Christian emperor in 313. He issued the Edict of Milan expressing tolerance for all religions thereby legalizing Christian worship. Various Christological debates about the human and divine nature of Jesus occupied the Christian Church for three centuries, and seven ecumenical councils were called to resolve them. Christianity played a prominent role in the development of Western civilization in Europe after the Fall of Rome. In the Early Middle Ages, missionary activities spread Christianity towards the west and the north. During the High Middle Ages, Eastern and Western Christianity grew apart, leading to the East–West Schism of 1054. Growing criticism of the Roman Catholic church and its corruption in the Late Middle Ages led to the Protestant Reformation and its related reform movements, which concluded with the European wars of religion, the return of tolerance as a theological and political option, and the Age of Enlightenment. In the twenty-first century, traditional Christianity has declined in the West, while new forms have developed and expanded throughout the world. Today, there are more than two billion Christians worldwide and Christianity has become the world's largest, and most widespread religion. Within the last century, the center of growth has shifted from West to East and from the North to the global South. Source: Wikipedia (en)