In the Greco-Roman world, ecclesia (Greek ἐκκλησίᾱ, ekklēsiā (Latin ecclesia) meaning "congregation, church") was used to refer to a lawful assembly, or a called legislative body. As early as Pythagoras, the word took on the additional meaning of a community with shared beliefs. This is the meaning taken in the Greek translation of the Hebrew Scriptures (the Septuagint), and later adopted by the Christian community to refer to the assembly of believers.
In the history of Western world (sometimes more precisely as Greco-Roman world) adopted by the Roman Empire and the Byzantine Empire, Christian ecclesiastical provinces were named by analogy with the secular Roman province as well as certain extraterritorial formations of western world in early medieval times (see Early Middle Ages). The administrative seat of each province is an episcopal see. In hierarchical Christian churches that have dioceses, a province is a collection of those dioceses (as a basic unit of administration).
Over the years certain provinces adopted the status of metropolis and have a certain degree of self-rule. A bishop of such province is called the metropolitan bishop or metropolitan. The Roman Catholic Church (both Latin and Eastern Catholic), the Orthodox Churches and the Anglican Communion all have provinces. These provinces are led by a metropolitan archbishop.
Ecclesiastical provinces first corresponded to the civil provinces of the Roman Empire. From the second half of the second century, the bishops of these provinces were accustomed to assemble on important occasions for common counsel in synods. From the end of that century the summons to attend these increasingly important synods was usually issued by the bishop of the capital or metropolis of the province, who also presided over the assembly, especially in the East. Important communications were also forwarded to the bishop of the provincial capital to be brought to the notice of the other bishops. Thus in the East during the third century the bishop of the provincial metropolis came gradually to occupy a certain superior position, and received the name of metropolitan.
At the First Council of Nicaea (325) this position of the metropolitan was taken for granted, and was made the basis for conceding to him definite rights over the other bishops and dioceses of the state province. In Eastern canon law since the fourth century (cf. also the Synod of Antioch of 341, can. ix), it was a principle that every civil province was likewise a church province under the supreme direction of the metropolitan, i.e. of the bishop of the provincial capital.