An ecclesiastical province is one of the basic forms of jurisdiction in Christian Churches with traditional hierarchical structure, including Western Christianity and Eastern Christianity. In general, an ecclesiastical province consists of several dioceses (or eparchies), one of them being the archdiocese (or archeparchy), headed by a metropolitan bishop or archbishop who has ecclesiastical jurisdiction over all other bishops of the province.
In the Greco-Roman world, ecclesia (Greek ἐκκλησία; Latin ecclesia) 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 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.
The borders of a religious institute's provinces are determined independently of any diocesan structure, and so the borders often differ from the 'secular', or diocesan, ecclesiastical provinces. The orders' provinces are usually far larger than a diocese, a secular province, or even a country, though sometimes they are smaller in an institute's heartland.
Most monastic orders are not organized by provinces. In general, they organise their administration through autonomous houses, in some cases grouped in larger families. For example, each Benedictine abbey is an independent foundation, but will often choose to group themselves into congregations based on historical connections.