It is usually considered that the bishops of an episcopal polity derive part of their authority from an unbroken, personal Apostolic Succession from the Twelve Apostles of Jesus. Bishops with such authority are known as the historical episcopate. Churches with this type of government usually believe that the Church requires episcopalian government.
For most of the written history of Christianity, episcopal government was the only form known to Christianity. (Some Baptists claim to descend from a continuous lineage of small churches which existed in parallel with the main stream of Catholic Christianity). This all changed at the Reformation. Many Protestant churches are now organized by either congregational or presbyterian church polities, both descended from the writings of John Calvin, a Protestant reformer working and writing independently following the break with the Roman Catholic Church precipitated by The Ninety-Five Theses of Martin Luther. However, the majority of Christians are still members of the historic churches of episcopal governance.
There are subtle differences in governmental principles among episcopal churches at the present time. To some extent the separation of episcopal churches can be traced to these differences in ecclesiology, that is, their theological understanding of church and church governance. The churches of Rome and Constantinople (the Catholic and Eastern Orthodox Churches in modern terms) have an episcopal government, as do the Oriental Orthodox, Assyrian, Anglican, some Lutheran and many Methodist churches.
In some systems, Bishops may be subject to higher ranking bishops (variously called archbishops, metropolitans, and/or patriarchs, depending upon the tradition; see also Bishop for further explanation of the varieties of bishops.) They also meet in councils or synods. These gatherings, subject to presidency by higher ranking bishops, may govern the judicatory which are represented in the council, though the synod or council may also be purely advisory.
Note that the presence of the office of "bishop" within a church is not proof of episcopal polity. For example, in The Church of Jesus Christ of Latter-day Saints an LDS bishop occupies the office that in an Anglican church would be occupied by a priest.
Also, episcopal polity is not usually a simple chain of command. Instead, some authority may be held, not only by synods and colleges of bishops, but by lay and clerical councils. Further, patterns of authority are subject to a wide variety of historical rights and honors which may cut across simple lines of authority.
Episcopal is also commonly used to distinguish between the various organizational structures of denominations. For instance, the word “presbyterian” (from the Greek πρεσβύτης, transliterated presbyteros) is used to describe a church governed by a hierarchy of assemblies of elected elders (see Presbyterian polity.) Similarly, “episcopal” is used to describe a church governed by bishops (Greek επίσκοπος, transliterated episcopos). Self-governed local churches (congregations), governed neither by elders nor bishops, are usually referred to as "congregational" (see Congregational polity.)
More specifically, the title Episcopal (capitalized) is applied to several churches historically based within Anglicanism (Episcopalianism) including those still in communion with the Church of England. See Episcopal Church (disambiguation).
Using these definitions, examples of specific episcopal churches include:
Some Lutheran churches practice congregational polity or a form of presbyterian polity. Others, including the Church of Sweden, practice episcopal polity; the Church of Sweden also counts its bishops among the historic episcopate as do some American Lutheran churches like the Anglo-Lutheran Catholic Church and the Lutheran Orthodox Church.
Many Methodist churches (see The United Methodist Church, among others) retain the form and function of episcopal polity. Since all trace their ordinations to an Anglican priest, John Wesley, it is generally considered that their bishops do not share in apostolic succession, though United Methodists still affirm that their bishops share in the historic episcopate.
Shortly after the Roman Emperor Constantine I legalized Christianity in 321, he also constructed an elaborate second capital of the Roman Empire located at Byzantium and renamed it Constantinople, in 324. The single Roman Empire was divided between these two autonomous administrative centers, Roman and Constantinopolitan, West and East, Latin speaking and Greek speaking. This remained the status quo through the fourth century.
In the fifth century, the Western Roman Empire declined and was overrun by German and Frankish peoples. Although the city of Rome was in ruins, distant from the seat of secular power, and constantly harassed by invaders, the Roman Patriarchate remained the center of the Western or Latin Church. Claiming the ancient primacy of Peter and the title of "Apostolic See," it remained the last court of episcopal appeal in serious matters for the whole Church, East and West.
However, the center of the civilized Roman world had shifted definitively to Constantinople, or New Rome, the capital of the Greek speaking Empire. Along with this shift, the effective administration of the Church in the Eastern Roman Empire also shifted. This practical eminence of Constantinople in the East is evident, first at the First Council of Constantinople 381, and then ecumenically at the Council of Chalcedon in 451.
Beginning with John the Faster, the Bishop of Constantinople (John IV, 582-595) adopted as a formal title for himself the by-then-customary honorific, Ecumenical Patriarch ("pre-eminent father for the civilized world") over the strong objections of Rome: a title based on the political prestige of Constantinople and its economic and cultural centrality in the Empire. In the following years, Rome's appeals to the East were based on the unique authority of the Apostolic See and the primacy of Peter, over against the powers of councils as defended by the East (councils, for example, had endorsed that lofty title which Rome contested).
The sometimes subtle differences between Eastern and Western conceptions of authority and its exercise produced a gradually widening rift between the Churches which continued with some occasional relief throughout the following centuries until the final rupture of the Great Schism (marked by two dates: 16 July, 1054, and the Council of Florence in 1439).
The conciliar idea of episcopal government continues in the Eastern Orthodox Church. In the Eastern Orthodox Church, the sixteen or so autocephalous primates are seen as collectively gathering around Christ, with other archbishops and bishops gathering around them, and so forth, in a model called "conciliar hierarchy". This is based in part on the vision in the book of Revelation of the 24 elders gathered around the throne of Christ, who are believed to represent the 12 patriarchs of Israel and the 12 apostles of Jesus Christ. There is no single patriarch with exclusive authority comparable to the Pope in Rome.
Both the Greek and Coptic Orthodox churches have a bishop in Alexandria, both of whom trace their apostolic succession back to the Apostle Mark (the Coptic bishop claims the title of Pope). There are official ongoing efforts in recent times to heal this ancient breach. Already, the two recognize each other's baptisms, chrismations, and marriages, making intermarriage much easier.
Anglicanism is the most prominent of the Reformation traditions to lay claim to the historic episcopate through apostolic succession in terms comparable to the various Catholic and Orthodox Communions. Anglicans assert unbroken episcopal succession in and through the Church of England back to St. Augustine of Canterbury and to the first century Roman province of Britannia. Although it is impossible to pinpoint an exact moment for the arrival of Catholic Christianity in the British Isles, we know from the Venerable Bede and other early sources that the faith clearly was planted in Great Britain and Ireland independent of Rome and prior to Augustine (see Celtic Christianity).
The legislation of Henry VIII effectively establishing the independence from Rome of the Church of England, did not alter its constitutional or pastoral structures. Royal supremacy was exercised through the extant legal structures of the church, whose leaders were bishops. Episcopacy was thus seen as a given of the Reformed Ecclesia Anglicana, and a foundation in the institution's appeal to ancient and apostolic legitimacy. What did change was that bishops were now seen to be ministers of the Crown for the spiritual government of its subjects. The influence of Richard Hooker was crucial to an evolution in this understanding in which bishops came to be seen in their more traditional role as ones who delegate to the presbyterate inherited powers, act as pastors to presbyters, and holding a particular teaching office with respect to the wider church.
Anglican opinion has differed as to the way in which episcopal government is de jure divino. On the one hand, the seventeenth century divine, John Cosin, held that episcopal authority is jure divino, but that it stemmed from "apostolic practice and the customs of the Church...[not] absolute precept that either Christ or His Apostles gave about it" (a view maintained also by Hooker). In contrast, Lancelot Andrewes and others held that episcopal government is derived from Christ via the apostles. Regardless, both parties viewed the episcopacy as bearing the apostolic function of oversight, which both includes, and derives from the power of ordination, and is normative for the governance of the church. The practice of apostolic succession both ensures the legitimacy of the church's mission and establishes the unity, communion, and continuity of the local church with the universal church. This formulation, in turn, laid the groundwork for an independent view of the church as a "sacred society" distinct from civil society, which was so crucial for the development of local churches as non-established entities outside England, and gave direct rise to the Catholic Revival and disestablishmentarianism within England.
Functionally, Anglican episcopal authority is expressed synodically, although individual provinces may accord their primate with more or less authority to act independently. Called variously "synods," "councils," or "conventions," they meet under episcopal chairmanship. In many jurisdictions, conciliar resolutions that have been passed require episcopal assent and/or consent to take force. Seen in this way, Anglicans often speak of "the bishop-in-synod" as the force and authority of episcopal governance. Such conciliar authority extends to the standard areas of doctrine, discipline, and worship, but in these regards is limited by Anglicanism's tradition of the limits of authority. Those limits are expressed in Article XXI of the Thirty-Nine Articles of Religion, ratified in 1571 (significantly, just as the Council of Trent was drawing to a close), which held that "General Councils...may err, and sometimes have erred...wherefore things ordained by them as necessary to salvation have neither strength nor authority, unless it may be declared that they be taken out of holy Scripture." Hence, Anglican jurisdictions have traditionally been conservative in their approach to either innovative doctrinal development or in encompassing actions of the church as doctrinal (see lex orandi, lex credendi).
Anglican synodical government, though varied in expression, is characteristically representative. Provinces of the Anglican Communion, their ecclesiastical provinces and dioceses are governed by councils consisting not only of bishops, but also representatives of the presbyterate and laity. The spread of increasingly democratic forms of representative governance has its origin in the formation of the first General Conventions of the American Episcopal Church in the 1780s, which established a "House of Bishops" and a "House of Deputies." In many jursidictions, there is also a third, clerical House. Resolutions may be voted on jointly or by each House, in the latter case requiring passage in all Houses to be adopted by the particular council.
There is no international juridical authority in Anglicanism, although the tradition's common experience of episcopacy, symbolised by the historical link with the See of Canterbury, along with a common and complex liturgical tradition, has provided a measure of unity. This has been reinforced by the Lambeth Conferences of Anglican Communion bishops, which first met in 1867. These conferences, though they propose and pass resolutions, are strictly consultative, and the intent of the resolutions are to provide guideposts for Anglican jurisdictions - not direction. The Conferences also express the function of the episcopate to demonstrate the ecumenical and Catholic nature of the church.
Churches that are members of the Anglican Communion are episcopal churches in polity, and some are named "Episcopal." However, some churches that self-identify as Anglican do not belong to the Anglican Communion, and not all episcopally-governed churches are Anglican. The Roman Catholic Church, the Old Catholic Churches (in full communion with, but not members of, the Anglican Communion), and the Eastern Orthodox churches are recognized, and also their bishops, by Anglicans.
The Reformed Church of France, the Reformed Church of Hungary, and the Lutheran churches in mainland Europe may sometimes be called "episcopal". In these latter cases, the form of government is not radically different from the presbyterian form, except that their councils of bishops have hierarchical jurisdiction over the local ruling bodies to a greater extent than in most Presbyterian and other Reformed churches. As mentioned, the Lutheran Church in Sweden and Finland are exceptions, claiming apostolic succession in a pattern somewhat like the Anglican churches. Otherwise, forms of polity are not mandated in the Lutheran churches, as it is not regarded as having doctrinal significance. Old World Lutheranism, for historical reasons, has tended to adopt Erastian theories of episcopal authority (by which church authority is to a limited extent sanctioned by secular government). In the United States, the Lutheran churches tend to adopt a form of government more comparable to congregationalism.
Although it never uses the term, The Church of Jesus Christ of Latter-day Saints (aka Mormons) is episcopal (rather than presbyterian or congregational) in the sense that it has a strict hierarchy of leadership from the local bishop up to a single prophet/president, believed to be personally authorized and guided by Jesus Christ. Local congregations (branches, wards, and stakes) have de jure boundaries by which members are allocated, and membership records are centralized. This system developed gradually from a more presbyterian polity (Joseph Smith's original title in 1830 was "First Elder") for pragmatic and doctrinal reasons, reaching a full episcopacy during the Nauvoo period (1839-1846).