Written by: Beth Davies-Stofka
Early churches adopted the hierarchical political organization of the Roman Empire. There was a single bishop, with authority over and responsibility for each local community. Each community also had presbyters, elders with whom the bishop consulted. The deacons assisted in administrative functions. In this way the first Christians instituted a distinction between the people, called the laity, and the community leaders, called clergy. Members of the clergy are ordained, or set apart for ministry. In the early Church, clergy were ordained by the ritual laying on of hands, conducted by the bishop, and most churches today continue with this or a similar practice.
When Christianity was formalized as the official religion of the Roman Empire (380), the Church institutionalized these roles. It incorporated local churches into an empire-wide hierarchy organized along the same political lines as those established by the Roman Empire. All churches and their bishops in a Roman province were presided over by an archbishop, or the bishop of the provincial capital. Next came regional groupings of provinces, all presided over by patriarchs. There were five patriarchates: Rome, Antioch in Syria, Alexandria in Egypt, Jerusalem, and Constantinople.
Bishops were often called papa or father, although in time papa, or pope, was reserved for the bishop in Rome. The pope acquired a primacy among bishops in part because of Rome's political position as the capital of the Roman Empire, but also because Rome was also the only diocese that claimed a significant connection to two leading apostles. Christian tradition places both Peter and Paul in Rome, and holds that both were executed there by the Emperor Nero in 64. While this is a subject of discussion and dispute among historians, Christian tradition names Peter as the first bishop of Rome.
After the Roman Emperor Constantine moved the capital of the empire from Rome to the city of Constantinople in 330, the bishop of Constantinople became the most influential patriarch of the East. The patriarchates of Antioch, Alexandria, and Jerusalem came under Muslim rule in the 7th century, and the status and importance of those patriarchates weakened as Christianity became a minority religion in those regions.