An ecumenical council is a conference of ecclesiastical dignitaries and theological experts convened to discuss and settle matters of Church doctrine and practice in which those entitled to vote are convoked from the whole world (oikoumene) and which secures the approbation of the whole Church.
Eastern Christianity comprises church families that developed outside the Occident, with major bodies including the Eastern Orthodox Church, the Oriental Orthodox churches, the Eastern Catholic churches, and the denominations descended from the Church of the East.
Chalcedonian Christianity refers to the Christian denominations adhering to the christological definitions and ecclesiological resolutions of the Council of Chalcedon, the Fourth Ecumenical Council held in 451. Chalcedonian Christians follow the Definition of Chalcedon, a religious doctrine concerning the divine and human natures of Jesus Christ. The great majority of Christian communions and confessions in the 21st century are Chalcedonian, but from the 5th to the 8th centuries the ascendancy of Chalcedonian Christology was not always certain.
The highest-ranking bishops in Eastern Orthodoxy, Oriental Orthodoxy, the Catholic Church, and the Church of the East are termed patriarchs.
Patriarchate is an ecclesiological term in Christianity, designating the office and jurisdiction of an ecclesiastical patriarch.
The Christian Church, also called the holy catholic church, is a Christian ecclesiological concept of a church invisible comprising all Christians. In this understanding, "Christian Church" or "catholic church" does not refer to a particular Christian denomination but to the "body" of all "believers", both defined in various ways. Other Christian traditions believe that these terms apply only to a specific concrete Christian institution, such as the Catholic Church, the Eastern Orthodox Church, the Oriental Orthodox Churches, or the Assyrian Church of the East; or to a group of institutions, as in the branch theory taught by some Anglicans.
A Christian denomination is a distinct religious body within Christianity, identified by traits such as a name, organization, leadership and doctrine. The Roman Catholic Church, Eastern Orthodox Church, and Oriental Orthodoxy, meaning the large majority, all self-describe as churches, whereas many Protestant denominations self-describe as congregations or fellowships. Divisions between one group and another are defined by authority and doctrine; issues such as the nature of Jesus, the authority of apostolic succession, ecclesiology, eschatology, and papal primacy may separate one denomination from another. Groups of denominations—often sharing broadly similar beliefs, practices, and historical ties—are sometimes known as "branches of Christianity". These branches differ in many ways, especially through differences in practices and belief.
The East–West Schism, also called the Great Schism and the Schism of 1054, was the break of communion between what are now the Roman Catholic Church and Eastern Orthodox Churches, which had lasted until the 11th century. The Schism was the culmination of theological and political differences between the Christian East and West which had developed over the preceding centuries.
Pentarchy is a model of Church organization historically championed in the Eastern Orthodox Church. It was formulated in the laws of Emperor Justinian I (527–565) of the Roman Empire. In the model, the Christian church is governed by the heads (patriarchs) of the five major episcopal sees of the Roman Empire: Rome, Constantinople, Alexandria, Antioch, and Jerusalem.
Catholicity is a concept pertaining to beliefs and practices widely accepted across numerous Christian denominations, most notably those that describe themselves as Catholic in accordance with the Four Marks of the Church, as expressed in the Nicene Creed of the First Council of Constantinople in 381: "[I believe] in one, holy, catholic, and apostolic Church."
In the history of Christianity, the first seven ecumenical councils include the following: the First Council of Nicaea in 325, the First Council of Constantinople in 381, the Council of Ephesus in 431, the Council of Chalcedon in 451, the Second Council of Constantinople in 553, the Third Council of Constantinople from 680–681 and finally, the Second Council of Nicaea in 787.
In the 5th century in Christianity, there were many developments which led to further fracturing of the State church of the Roman Empire. Emperor Theodosius II called two synods in Ephesus, one in 431 and one in 449, that addressed the teachings of Patriarch of Constantinople Nestorius and similar teachings. Nestorius had taught that Christ's divine and human nature were distinct persons, and hence Mary was the mother of Christ but not the mother of God. The Council rejected Nestorius' view causing many churches, centered on the School of Edessa, to a Nestorian break with the imperial church. Persecuted within the Roman Empire, many Nestorians fled to Persia and joined the Sassanid Church thereby making it a center of Nestorianism. By the end of the 5th century, the global Christian population was estimated at 10-11 million. In 451 the Council of Chalcedon was held to clarify the issue further. The council ultimately stated that Christ's divine and human nature were separate but both part of a single entity, a viewpoint rejected by many churches who called themselves miaphysites. The resulting schism created a communion of churches, including the Armenian, Syrian, and Egyptian churches, that is today known as Oriental Orthodoxy. In spite of these schisms, however, the imperial church still came to represent the majority of Christians within the Roman Empire.
In 6th-century Christianity, Roman Emperor Justinian launched a military campaign in Constantinople to reclaim the western provinces from the Germans, starting with North Africa and proceeding to Italy. Though he was temporarily successful in recapturing much of the western Mediterranean he destroyed the urban centers and permanently ruined the economies in much of the West. Rome and other cities were abandoned. In the coming centuries the Western Church, as virtually the only surviving Roman institution in the West, became the only remaining link to Greek culture and civilization.
In 9th-century Christianity, Charlemagne was crowned as Holy Roman Emperor, which continued the Photian schism.
The following outline is provided as an overview of and topical guide to Christianity:
Christianity in late antiquity traces Christianity during the Christian Roman Empire – the period from the rise of Christianity under Emperor Constantine, until the fall of the Western Roman Empire. The end-date of this period varies because the transition to the sub-Roman period occurred gradually and at different times in different areas. One may generally date late ancient Christianity as lasting to the late 6th century and the re-conquests under Justinian of the Byzantine Empire, though a more traditional end-date is 476, the year in which Odoacer deposed Romulus Augustus, traditionally considered the last western emperor.
With the Edict of Thessalonica in 380 AD, Emperor Theodosius I made Nicene Christianity the Empire's state religion. The Eastern Orthodox Church, Oriental Orthodoxy, and the Catholic Church each claim to stand in continuity with the church to which Theodosius granted recognition, but do not look on it as specific to the Roman Empire.
The history of Eastern Orthodox Christian theology begins with the life of Jesus and the forming of the Christian Church. Major events include the Chalcedonian schism with the Oriental Orthodox miaphysites, the Iconoclast controversy, the Photian schism, the Great Schism between East and West, and the Hesychast controversy. The period after the Second World War saw a re-engagement with the Greek, and more recently Syriac, Fathers that included a rediscovery of the theological works of St. Gregory Palamas, which has resulted in a renewal of Orthodox theology in the 20th and 21st centuries.
The Church Fathers, Early Church Fathers, Christian Fathers, or Fathers of the Church were ancient and influential Christian theologians and writers who established the intellectual and doctrinal foundations of Christianity. There is no definitive list. The historical period during which they flourished is referred to by scholars as the Patristic Era ending approximately around AD 700.
The following outline is provided as an overview of and topical guide to the Catholic Church:
