Eastern Orthodox Church

thumb|[[Christ Pantocrator (Sinai)|Christ Pantocrator, sixth century, Saint Catherine's Monastery, Sinai; the oldest known icon of Christ, in one of the oldest monasteries in the world]]

The Eastern Orthodox Church, officially the Orthodox Catholic Church, also known as the Greek Orthodox Church

The Eastern Orthodox Church operates as a communion of autocephalous churches, each governed by its bishops via local synods. The church has no central doctrinal or governmental authority analogous to the pope of the Catholic Church. Nevertheless, the Ecumenical Patriarch of Constantinople is recognised by them as primus inter pares (), a title held by the patriarch of Rome prior to the East–West Schism.

As one of the oldest surviving religious institutions in the world, the Eastern Orthodox Church has played an especially prominent role in the history and culture of Eastern and Southeastern Europe. Since 2018, there has been an ongoing schism between Constantinople and Moscow, with the two not in full communion with each other.

Eastern Orthodox theology is based on the Scriptures and holy tradition, which incorporates the dogmatic decrees of the seven ecumenical councils, and the teaching of the Church Fathers. The church teaches that it is the one, holy, catholic and apostolic church established by Jesus Christ in his Great Commission, and that its bishops are the successors of Christ's apostles. It maintains that it practises the original Christian faith, as passed down by holy tradition. Its patriarchates, descending from the pentarchy, and other autocephalous and autonomous churches, reflect a variety of hierarchical organisation. It recognises seven major sacraments (which are called holy mysteries), of which the Eucharist is the principal one, celebrated liturgically in synaxis. The church teaches that through consecration invoked by a priest, the sacrificial bread and wine become the body and blood of Christ. The Virgin Mary is venerated in the Eastern Orthodox Church as the Theotokos, which means 'God-bearer', and she is honoured in devotions.

The churches of Constantinople, Alexandria, Jerusalem, and Antioch—except for some breaks of communion such as the Photian schism or the Acacian schism—shared communion with the Church of Rome until the East–West Schism in 1054. The 1054 schism was the culmination of mounting theological, political, and cultural disputes, particularly over the authority of the pope, between those churches. Before the Council of Ephesus in AD 431, the Church of the East also shared in this communion, as did the various Oriental Orthodox Churches before the Council of Chalcedon in AD 451, all separating primarily over differences in Christology.

The Eastern Orthodox Church is the primary religious confession in Russia, Ukraine, Romania, Greece, Belarus, Serbia, Bulgaria, Georgia, Moldova, North Macedonia, Cyprus, and Montenegro. Eastern Orthodox Christians are also one of the main religious groups in Estonia, Bosnia and Herzegovina, Kosovo and Latvia as well as a significant group in Syria, Lebanon, and other countries in the Middle East. Roughly half of Eastern Orthodox Christians live in the post Eastern Bloc countries, mostly in Russia. The communities in the former Byzantine regions of North Africa and the Eastern Mediterranean are among the oldest Orthodox communities from the Middle East, which are decreasing due to forced migration driven by increased religious persecution. Eastern Orthodox communities outside Western Asia, Asia Minor, Caucasia and Eastern Europe, including those in North America, Western Europe, and Australia, have been formed through diaspora, conversions, and missionary activity.

Name and characteristics

Definition

The Eastern Orthodox Church is defined as the Eastern Christians which recognise the seven ecumenical councils and usually are in communion with the Ecumenical Patriarchate, the Patriarchate of Alexandria, the Patriarchate of Antioch, and the Patriarchate of Jerusalem. The Eastern Orthodox churches "are defined positively by their adherence to the dogmatic definitions of the seven [ecumenical] councils, by the strong sense of not being a sect or a denomination but simply continuing the Christian church, and, despite their varied origins, by adherence to the Byzantine rite". Those churches are negatively defined by their rejection of papal immediate and universal supremacy.

The seven ecumenical councils recognised by the Eastern Orthodox churches are: Nicaea I, Constantinople I, Ephesus, Chalcedon, Constantinople II, Constantinople III, and Nicaea II. "By an agreement that appears to be in place in the [Eastern] Orthodox world, possibly the council held in 879 to vindicate the Patriarch Photius will at some future date be recognized as the eighth [ecumenical] council" by the Eastern Orthodox Church. The Antiochian Orthodox Archdiocese of North America estimated there are 1,416 members of the Western Rite vicariate in 24 parishes. With roughly 3,000 members worldwide, spread across about 50 scattered parishes, Western Rite Orthodoxy remains a very small minority within the Eastern Orthodox Church.

Name

The official name of the Eastern Orthodox Church is the "Orthodox Catholic Church". It is the name by which the church refers to itself<!--

This adaptation from The Orthodox Church, Kallistos Ware, 1993, was first produced by the monks of Decani Monastery, Kosovo. It was placed on the Orthodox Christian Information Center website after the monastery website went defunct following the Kosovo conflict. It has been used among various Orthodox church websites to provide an introduction to the faith. – User Evensteven, 3 May 2014

--> and which is issued in its liturgical or canonical texts. Eastern Orthodox theologians refer to the church as Catholic. This name and longer variants containing "Catholic" are also recognised and referenced in other books and publications by secular or non-Eastern Orthodox writers. The catechism of Philaret (Drozdov) of Moscow published in the 19th century is titled: The Longer Catechism of the Orthodox, Catholic, Eastern Church ().

In keeping with the church's teaching on universality and with the Nicene Creed, Eastern Orthodox authorities such as Raphael of Brooklyn have insisted that the full name of the church has always included the term "Catholic", as in "Holy Orthodox Catholic Apostolic Church".

From ancient times through the first millennium, Greek was the most prevalent shared language in the demographic regions where the Byzantine Empire flourished, and Greek, being the language in which the New Testament was written, was the primary liturgical language of the church. For this reason, the eastern churches were sometimes identified as "Greek" (in contrast to the "Roman" or "Latin" church, which used a Latin translation of the Bible), even before the Great Schism of 1054. After 1054, "Greek Orthodox" or "Greek Catholic" marked a church as being in communion with Constantinople, much as "Catholic" did for communion with the Catholic Church.

In Hungarian, the church is still commonly called "Eastern Greek" (). This identification with Greek, however, became increasingly confusing with time. Missionaries brought Eastern Orthodoxy to many regions without ethnic Greeks, where the Greek language was not spoken. In addition, struggles between Rome and Constantinople to control parts of Southeastern Europe resulted in the conversion of some churches to the Catholic Church, which then also used "Greek Catholic" to indicate their continued use of the Byzantine rites. Today, only a minority of Eastern Orthodox adherents use Greek as the language of worship.

"Eastern", then, indicates the geographical element in the church's origin and development, while "Orthodox" indicates the faith, as well as communion with the Ecumenical Patriarchate of Constantinople. While the Eastern Orthodox Church continues officially to call itself "Catholic", for reasons of universality, the common title of "Eastern Orthodox Church" avoids casual confusion with the Catholic Church.

Orthodoxy

thumb|[[Emperor Constantine presents a representation of the city of Constantinople as tribute to an enthroned Mary and baby Jesus in this church mosaic (Hagia Sophia, ).]]

The first known use of the phrase "the catholic Church" (he katholike ekklesia) occurred in a letter written from one Greek church to another (Ignatius of Antioch to the Smyrnaeans). The letter states: "Wheresoever the bishop shall appear, there let the people be, even as where Jesus may be, there is the universal [katholike] Church." Thus, almost from the beginning, Christians referred to the Christian Church as the "one, holy, catholic (from the Greek καθολική, 'according to the whole, universal') and apostolic Church".

The dual meanings of doxa, with "glory" or "glorification" (of God by the church and of the church by God), especially in worship, yield the pair "correct belief" and "true worship". Together, these express the core of a fundamental teaching about the inseparability of belief and worship and their role in drawing the church together with Christ. All Slavic Orthodox churches use the title Pravoslavie (), meaning "correctness of glorification", to denote what is in English Orthodoxy, while the Georgians use the title Martlmadidebeli ().

The term "Eastern Church" (the geographic east in the East–West Schism) has been used to distinguish it from western Christendom (the geographic West, which at first came to designate the Catholic communion, later also the various Protestant and Anglican branches). "Eastern" is used to indicate that the highest concentrations of the Eastern Orthodox Church presence remain in the eastern part of the Christian world, although it is growing worldwide. Orthodox Christians throughout the world use various ethnic or national jurisdictional titles, or more inclusively, the title "Eastern Orthodox", "Orthodox Catholic", or simply "Orthodox".

What unites Orthodox Christians is the catholic faith as carried through holy tradition. That faith is expressed most fundamentally in scripture and worship, and the latter most essentially through baptism and in the Divine Liturgy.

The lines of even this test can blur, however, when differences that arise are not due to doctrine, but to recognition of jurisdiction. As the Eastern Orthodox Church has spread into the West and over the world, the church as a whole has yet to sort out all the inter-jurisdictional issues that have arisen in the expansion, leaving some areas of doubt about what is proper church governance. Moreover, as in the ancient church persecutions, the aftermath of persecutions of Christians in communist nations has complicated some issues of governance that have yet to be completely resolved.

All members of the Eastern Orthodox Church profess the same faith, regardless of race or nationality, jurisdiction or local custom, or century of birth. Holy tradition encompasses the understandings and means by which that unity of faith is transmitted across boundaries of time, geography, and culture. It is a continuity that exists only inasmuch as it lives within Christians themselves. It is not static, nor an observation of rules, but rather a sharing of observations that spring both from within and also in keeping with others, even others who lived lives long past. The church proclaims the Holy Spirit maintains the unity and consistency of holy tradition to preserve the integrity of the faith within the church, as given in the scriptural promises.

Orthodoxy asserts that its shared beliefs, and its theology, exist within holy tradition and cannot be separated from it, and that their meaning is not expressed in mere words alone; that doctrine cannot be understood unless it is prayed; and that it must also be lived in order to be prayed, that without action, the prayer is idle, empty, and in vain, and therefore the theology of demons.

Catholicity

thumb|upright=0.9|[[Eastern Orthodoxy|Eastern Orthodox icon of St. John the Baptist, 14th century, North Macedonia]]

The Eastern Orthodox Church considers itself to be both orthodox and catholic. The doctrine of the Catholicity of the Church, as derived from the Nicene Creed, is essential to Eastern Orthodox ecclesiology. The term Catholicity of the Church (Greek: ) is used in its original sense, as a designation for the universality of the Christian Church, centred around Christ. Therefore, the Eastern Orthodox notion of catholicity is not centred around any singular see, unlike the Catholic Church which has one earthly centre.

Due to the influence of the Catholic Church in the West, where the English language itself developed, the words "catholic" and "catholicity" are sometimes used to refer to that church specifically. However, the more prominent dictionary sense given for general use is still the one shared by other languages, implying breadth and universality, reflecting comprehensive scope. In a Christian context, the Christian Church, as identified with the original church founded by Christ and his apostles, is said to be catholic (or universal) in regard to its union with Christ in faith.

Just as Christ is indivisible, so are union with him and faith in him, whereby the Christian Church is "universal", unseparated, and comprehensive, including all who share that faith. Orthodox bishop Kallistos Ware has called that "simple Christianity". That is the sense of early and patristic usage wherein the church usually refers to itself as the "Catholic Church", whose faith is the "Orthodox faith". It is also the sense within the phrase "one, holy, catholic, and apostolic Church", found in the Nicene Creed, and referred to in Orthodox worship, e.g. in the litany of the catechumens in the Divine Liturgy.

With the mutual excommunications of the East–West Schism in 1054, the churches in Rome and Constantinople each viewed the other as having departed from the true church, leaving a smaller but still-catholic church in place. Each retained the "Catholic" part of its title, the "Roman Catholic Church" (or Catholic Church) on the one hand, and the "Orthodox Catholic Church" on the other, each of which was defined in terms of inter-communion with either Rome or Constantinople. While the Eastern Orthodox Church recognises what it shares in common with other churches, including the Catholic Church, it sees catholicity in terms of complete union in communion and faith, with the Church throughout all time, and the sharing remains incomplete when not shared fully.

History

Early Church

thumb|An early Christian "[[Ichthys" (fish) inscription from ancient Ephesus|210x210px]]

Paul and the Apostles travelled extensively throughout the Roman Empire, including Asia Minor, establishing churches in major communities, with the first churches appearing in Jerusalem and the Holy Land, then in Antioch, Ethiopia, Egypt, Rome, Alexandria, Athens, Thessalonica, Illyricum, and Byzantium, which centuries later would become prominent as the New Rome. Christianity encountered considerable resistance in the Roman Empire, mostly because its adherents refused to comply with the demands of the Roman state—often even when their lives were threatened—by offering sacrifices to the pagan gods. Despite persecution, skepticism, and initial social stigma, the Christian Church spread, particularly following the conversion of Emperor Constantine I in AD 312. as of major importance.

Ecumenical councils

thumb|[[Icon depicting Constantine the Great, accompanied by the bishops of the First Council of Nicaea (325), holding the Niceno-Constantinopolitan Creed of 381. First line of main text in Greek: . Translation: "We believe in one God, the Father, the Almighty, Maker of heaven and earth."]]

Several doctrinal disputes from the fourth century onwards led to the calling of ecumenical councils. In the Orthodox Church, an ecumenical council is the supreme authority that can be invoked to resolve contested issues of the faith. As such, these councils have been held to resolve the most important theological matters that came to be disputed within the Christian Church. Many lesser disagreements were resolved through local councils in the areas where they arose, before they grew significant enough to require an ecumenical council.

There are seven councils authoritatively recognised as ecumenical by the Eastern Orthodox Church:

The First Ecumenical Council was convoked by the Roman Emperor Constantine at Nicaea in 325 and presided over by the Patriarch Alexander of Alexandria, with over 300 bishops condemning the view of Arius that the Son is a created being inferior to the Father.
The Second Ecumenical Council was held at Constantinople in 381, presided over by the Patriarchs of Alexandria and Antioch, with 150 bishops, defining the nature of the Holy Spirit against those asserting His inequality with the other persons of the Trinity.
The Third Ecumenical Council is that of Ephesus in 431, presided over by the Patriarch of Alexandria, with 250 bishops, which affirmed that Mary is truly "Birthgiver" or "Mother" of God (Theotokos), contrary to the teachings of Nestorius.
The Fourth Ecumenical Council is that of Chalcedon in 451, Patriarch of Constantinople presiding, 500 bishops, affirmed that Jesus is truly God and truly man, without mixture of the two natures, contrary to Monophysite teaching.
The Fifth Ecumenical Council is the second of Constantinople in 553, interpreting the decrees of Chalcedon and further explaining the relationship of the two natures of Jesus; it also condemned the alleged teachings of Origen on the pre-existence of the soul, etc.
The Sixth Ecumenical Council is the third of Constantinople in 681; it declared that Christ has two wills of his two natures, human and divine, contrary to the teachings of the Monothelites.
The Seventh Ecumenical Council was called under the Empress Regent Irene of Athens in 787, known as the second of Nicaea. It supports the veneration of icons while forbidding their worship. It is often referred to as "The Triumph of Orthodoxy".

There are also two other councils which are considered ecumenical by some Eastern Orthodox:

The Fourth Council of Constantinople was called in 879. It restored Photius to his See in Constantinople and condemned any alteration of the Nicene-Constantinopolitan Creed of 381.
The Fifth Council of Constantinople was actually a series of councils held between 1341 and 1368. It affirmed the hesychastic theology of Gregory Palamas and condemned the philosopher Barlaam of Calabria.

Other major councils

In addition to these councils, there have been a number of other significant councils meant to further define the Eastern Orthodox position. They are the Synods of Constantinople, in 1484, 1583, 1755, 1819, and 1872, the Synod of Iași in 1642, and the Pan-Orthodox Synod of Jerusalem in 1672. Another council convened in June 2016 to discuss many modern phenomena, other Christian confessions, Eastern Orthodoxy's relation with other religions and fasting disciplines.

Roman and Byzantine Empire

thumb|The [[Hagia Sophia, the largest church in the world and patriarchal basilica of Constantinople for nearly a thousand years, later converted into a mosque, then a museum, then back to a mosque]]

Constantinople is generally considered to be the centre and the "cradle of Orthodox Christian civilisation". From the mid-5th century to the early 13th century, Constantinople was the largest and wealthiest city in Europe. Eastern Christian culture reached its golden age during the high point of the Byzantine Empire and continued to flourish in Ukraine and Russia, after the fall of Constantinople. Numerous autocephalous churches were established in Europe: Greece, Georgia, Ukraine, as well as in Russia and Asia.

In the 530s the Church of the Holy Wisdom (Hagia Sophia) was built in Constantinople under Emperor Justinian I. Beginning with subsequent Byzantine architecture, Hagia Sophia became the paradigmatic Orthodox church form and its architectural style was emulated by Ottoman mosques a thousand years later. Being the episcopal see of the ecumenical patriarch of Constantinople, it remained the world's largest cathedral for nearly a thousand years, until Seville Cathedral was completed in 1520. Hagia Sophia has been described as "holding a unique position in the Christian world", and it is considered the epitome of Byzantine architecture and is said to have "changed the history of architecture".

Early schisms

There are the "Nestorian" churches resulted from the reaction of the Council of Ephesus (431), which are the earliest surviving Eastern Christian churches that keep the faith of only the first two ecumenical councils, i.e., the First Council of Nicaea (325) and the First Council of Constantinople (381) as legitimate. "Nestorian" is an outsider's term for a tradition that predated the influence of Nestorius, the origin of which might lie in certain sections of the School of Antioch or via Nestorius' teachers Theodore of Mopsuestia or Diodore of Tarsus. The modern incarnation of the "Nestorian Church" is commonly referred to as "the Assyrian Church" or fully as the Assyrian Church of the East.

The church in Egypt (Patriarchate of Alexandria) split into two groups following the Council of Chalcedon (451), over a dispute about the relation between the divine and human natures of Jesus. Eventually this led to each group anathematising the other. Those that remained in communion with the other patriarchs (by accepting the Council of Chalcedon) are known today as the Greek Orthodox Church of Alexandria, where the adjective "Greek" refers to their ties to the Greek-speaking culture of the Byzantine Empire.

Those who disagreed with the findings of the Council of Chalcedon were the majority in Egypt. Today, they are known as the Coptic Orthodox Church, having maintained a separate patriarchate. The Coptic Orthodox Church is currently the largest Christian church in Egypt and the entire Middle East. Likewise, in the Levant and Mesopotamia, another schism occurred to the Patriarchate of Antioch, resulting in the establishment of two parallel patriarchates which endure today: the Syriac Orthodox Church of Antioch and the Greek Orthodox Church of Antioch.

Those who disagreed with the Council of Chalcedon are called Oriental Orthodox to distinguish them from the Eastern Orthodox, who accepted the Council of Chalcedon. Oriental Orthodox are also sometimes referred to as "non-Chalcedonians" or "anti-Chalcedonians". The Oriental Orthodox Church denies that it is monophysite and prefers the term miaphysite, to denote the "united" nature of Jesus (two natures united into one composite nature) consistent with Cyril's theology: "The term union ... signifies the concurrence in one reality of those things which are understood to be united" and "the Word who is ineffably united with it in a manner beyond all description" (Cyril of Alexandria, On the Unity of Christ). This is also defined in the Coptic liturgy, where it is mentioned "He made it [his humanity] one with his divinity without mingling, without confusion and without alteration", and "His divinity parted not from his humanity for a single moment nor a twinkling of an eye." They do not accept the teachings of Eutyches, or Eutychianism. Both the Eastern Orthodox and Oriental Orthodox churches formally believe themselves to be the continuation of the true church.

Conversion of the South and East Slavs

In the ninth and tenth centuries, Christianity made great inroads into pagan Europe, including Bulgaria (864) and later Kievan Rus' (988). This work was made possible by Cyril and Methodius of Thessaloniki, two brothers chosen by Byzantine emperor Michael III to fulfil the request of Rastislav of Moravia for teachers who could minister to the Moravians in their own language. Cyril and Methodius began translating the divine liturgy, other liturgical texts, and the Gospels along with some other scriptural texts into local languages; with time, as these translations were copied by speakers of other dialects, the hybrid literary language Church Slavonic was created. Originally sent to convert the Slavs of Great Moravia, Cyril and Methodius were forced to compete with Frankish missionaries from the Roman diocese; their disciples were driven out of Great Moravia in AD 886 and emigrated to Bulgaria.

thumb|upright=1.25|The baptism of [[Olga of Kiev|Princess Olga in Constantinople, a miniature from the Radziwiłł Chronicle]]

After the Christianisation of Bulgaria in 864, the disciples of Cyril and Methodius in Bulgaria, the most important being Clement of Ohrid and Naum of Preslav, were of great importance to the Orthodox faith in the First Bulgarian Empire. In a short time they managed to prepare and instruct the future Bulgarian clergy into the biblical texts and in AD 870 the Fourth Council of Constantinople granted the Bulgarians the oldest organised autocephalous Slavic Orthodox Church, which shortly thereafter became Patriarchate. The success of the conversion of the Bulgarians facilitated the conversion of the East Slavs. A major event in this effort was the development of the Cyrillic script in Bulgaria, at the Preslav Literary School in the ninth century; this script, along with the liturgical Old Church Slavonic, also called Old Bulgarian, was declared official in Bulgaria in 893.

The work of Cyril and Methodius and their disciples had a major impact on the Serbs as well. They accepted Christianity collectively along familial and tribal lines, a gradual process that occurred between the seventh and ninth centuries. In commemoration of their baptisms, each Serbian family or tribe began to celebrate an exclusively Serbian custom called Slava (patron saint) in a special way to honour the saint on whose day they received the sacrament of baptism. It is the most solemn day of the year for all Serbs of the Orthodox faith and has played a role of vital importance in the history of the Serbian people. Slava remains a celebration of the conversion of the Serbian people, which the church blessed and proclaimed a church institution.

The missionaries to the East and South Slavs had great success in part because they used the people's native language rather than Greek, the predominant language of the Byzantine Empire, or Latin, as the Roman priests did.

Great Schism (1054)

In the 11th century, what was recognised as the Great Schism took place between Rome and Constantinople, which led to separation between the Church of the West, the Catholic Church, and the Eastern Byzantine churches, now the Orthodox. There were doctrinal issues like the filioque clause and the authority of the Pope involved in the split, but these were greatly exacerbated by political factors of both Church and state, and by cultural and linguistic differences between Latins and Greeks. Regarding papal supremacy, the Eastern half grew disillusioned with the Pope's centralisation of power, as well as his blatant attempts of excluding the Eastern half in regard to papal approvals. It had previously been the case that the emperor would have a say when a new Pope was elected, but towards the high Middle Ages, the Christians in Rome were slowly consolidating power and removing Byzantine influence. However, even before this exclusionary tendency from the West, well before 1054, the Eastern and Western halves of the Church were in perpetual conflict, particularly during the periods of Eastern iconoclasm and the Photian schism.

thumb|Latin Crusaders [[Siege of Constantinople (1204)|sacking the city of Constantinople, the capital of the Eastern Orthodox–controlled Byzantine Empire, in 1204]]

The final breach is often considered to have arisen after the capture and sacking of Constantinople by the Fourth Crusade in 1204; the final break with Rome occurred circa 1450. The sacking of Church of Holy Wisdom and establishment of the Latin Empire as a seeming attempt to supplant the Orthodox Byzantine Empire in 1204 is viewed with some rancour to the present day. In 2004, Pope John Paul II extended a formal apology for the sacking of Constantinople in 1204, which had also been strongly condemned by the Pope at the time, Innocent III; the apology was formally accepted by Patriarch Bartholomew of Constantinople. However, many items stolen during this time, such as holy relics and riches, are still held in various European cities, particularly Venice.

Reunion was attempted twice, at the 1274 Second Council of Lyon and the 1439 Council of Florence. The Council of Florence briefly reestablished communion between East and West, which lasted until after the fall of Constantinople in 1453. In each case, however, the councils were rejected by the Orthodox people as a whole, and the union of Florence also became very politically difficult after Constantinople came under Ottoman rule. However, in the time since, several local Orthodox Christian churches have renewed union with Rome, known as the Eastern Catholic Churches. Recent decades have seen a renewal of ecumenical spirit and dialogue between the Catholic and Orthodox churches.

Greek Church under Ottoman rule

The Byzantine Empire never fully recovered from the sack of Constantinople in 1204. Over the next two centuries, it entered a precipitous decline in both territory and influence. In 1453, a much-diminished Byzantine Empire fell to the Ottoman Empire, ending what was once the most powerful state in the Orthodox Christian world, if not in all Christendom. By this time Egypt, another major centre of Eastern Christianity, had been under Muslim control for some seven centuries; most Eastern Orthodox communities across southeastern Europe gradually came under Ottoman rule by the 16th century.

Under the Ottomans, the Greek Orthodox Church acquired substantial power as an autonomous millet. The ecumenical patriarch was the religious and administrative ruler of the Rûm, an Ottoman administrative unit meaning "Roman", which encompassed all Orthodox subjects of the Empire regardless of ethnicity. While legally subordinate to Muslims and subject to various restrictions, the Orthodox community was generally tolerated until the rise of nationalist movements in the late 19th and early 20th centuries, and left to govern its own internal affairs, both religiously and legally. Until the empire's dissolution in the early 20th century, Orthodox Christians would remain the largest non-Muslim minority, and at times among the wealthiest and most politically influential.

thumb|Greek Orthodox massacred during the [[Greek genocide in Smyrna in 1922]]

During the period 1914–1923 in Asia Minor (Anatolia) the Greek genocide took place by the Ottomans. During the Greek genocide, many Orthodox Christians were persecuted and killed. The culmination of the martyrdom was the Asia Minor Catastrophe with the killing of a large number of Orthodox. Among them, 347 clergymen of the Smyrna region and Metropolitan of Smyrna Chrysostomos were tortured and killed. The period 1923–1924 was followed by the obligatory population exchange between Greece and Turkey.

Russian Orthodox Church in the Russian Empire

thumb|[[Uspenski Cathedral, a main cathedral of the Finnish Orthodox Church in Helsinki, Finland, was built under Imperial Russia.]]

By the time most Orthodox communities came under Muslim rule in the mid-15th century, Orthodoxy was very strong in Russia, which had maintained close cultural and political ties with the Byzantine Empire; roughly two decades after the fall of Constantinople, Ivan III of Russia married Sophia Palaiologina, a niece of the last Byzantine Emperor Constantine XI, and styled himself Tsar ("Caesar") or imperator. In 1547, his grandson Ivan IV, a devout Orthodox Christian, cemented the title as "Tsar of All Rus", establishing Russia's first centralised state with divinely appointed rulers. In 1589, the Patriarchate of Constantinople granted autocephalous status to Moscow, the capital of what was now the largest Orthodox Christian polity; the city thereafter referred to itself as the Third Rome —<nowiki/>the cultural and religious heir of Constantinople.

Until 1666, when Patriarch Nikon was deposed by the tsar, the Russian Orthodox Church had been independent of the State. In 1721, the first Russian Emperor, Peter I, abolished completely the patriarchate and effectively made the church a department of the government, ruled by a most holy synod composed of senior bishops and lay bureaucrats appointed by the Emperor himself. Over time, Imperial Russia would style itself a protector and patron of all Orthodox Christians, especially those within the Ottoman Empire.

For nearly 200 years, until the Bolsheviks' October Revolution of 1917, the Russian Orthodox Church remained, in effect, a governmental agency and an instrument of tsarist rule. It was used to varying degrees in imperial campaigns of Russification, and was even allowed to levy taxes on peasants. The church's close ties with the state came to a head under Nicholas I (1825–1855), who explicitly made Orthodoxy a core doctrine of imperial unity and legitimacy. The Orthodox faith became further tied to Russian identity and nationalism, while the church was further subordinated to the interests of the state. Consequently, Russian Orthodox Church, along with the imperial regime to which it belonged, came to be presented as an enemy of the people by the Bolsheviks and other Russian revolutionaries.

Eastern Orthodox churches under Communist rule

After the October Revolution of 1917, part of the clergy of the Russian Orthodox Church fled abroad to escape Bolshevik persecutions, founding an independent church in exile, which reunified with its Russian counterpart in 2007. Others formed the present-day Orthodox Church in America, and the American Orthodox Catholic Church (the latter whose bishops were considered episcopi vagantes, yet also accepted back into mainstream Orthodoxy). Some actions against Orthodox priests and believers along with execution included torture, being sent to prison camps, labour camps or mental hospitals. In the first five years after the Bolshevik revolution, 28 bishops and 1,200 priests were executed.

After Nazi Germany's attack on the Soviet Union in 1941, Joseph Stalin revived the Russian Orthodox Church to intensify patriotic support for the war effort. By 1957 about 22,000 Russian Orthodox churches had become active. However, in 1959, Nikita Khrushchev initiated his own campaign against the Russian Orthodox Church and forced the closure of about 12,000 churches. It is estimated that 50,000 clergy had been executed between the revolution and the end of the Khrushchev era. Members of the church hierarchy were jailed or forced out, their places taken by docile clergy, many of whom had ties with the KGB. By 1985 fewer than 7,000 churches remained active. In some other Communist states such as Romania, the Romanian Orthodox Church as an organisation enjoyed relative freedom and even prospered, albeit under strict secret police control. That, however, did not rule out demolishing churches and monasteries as part of broader systematisation (urban planning), and state persecution of individual believers. As an example of the latter, Romania stands out as a country which ran a specialised institution where many Orthodox (along with people of other faiths) were subjected to psychological punishment or torture and mind control experimentation in order to force them give up their religious convictions. However, this was only supported by one faction within the regime, and lasted only three years. The Communist authorities closed down the prison in 1952, and punished many of those responsible for abuses (twenty of them were sentenced to death).

Post-communism to 21st century

Since the dissolution of the Soviet Union, and the subsequent Fall of Communist governments across the Orthodox world, there has been marked growth in Christian Orthodoxy, particularly in Russia. According to the Pew Research Religion & Public Life Project, between 1991 and 2008, the share of Russian adults identifying as Orthodox Christian rose from 31 per cent to 72 per cent, based on analysis of three waves of data (1991, 1998 and 2008) from the International Social Survey Programme (ISSP), a collaborative effort involving social scientists in about 50 countries.

Pew research conducted in 2017 found a doubling in the global Orthodox population since the early 20th century, with the greatest resurgence in Russia. In the former Soviet Union—where the largest Orthodox communities live—self-identified Orthodox Christians generally report low levels of observance and piety: In Russia, only 6% of Orthodox Christian adults reported attending church at least weekly, 15% say religion is "very important" in their lives, and 18% say they pray daily; other former Soviet republics display similarly low levels of religious observance.

Moscow–Constantinople schisms

1996

Since 1923, the Orthodox Church of Estonia separated from the Russian Orthodox Church due to the imprisonment of Patriarch Tikhon of Moscow, and the church in the Republic of Estonia falling out of communication with the Russian Church. They petitioned to be placed under direct control of the Ecumenical Patriarch of Constantinople, operating as an autonomous church. In 1944 the Soviet Union annexed Estonia and outlawed the Orthodox Church of Estonia, forcefully bringing their churches back under the control of the Moscow Patriarch. However, the church's Primate, Metropolitan Aleksander, fled to Sweden with 21 clergymen and 8,000 followers and established a synod there operating there throughout the Cold War.

In 1993, the synod of the Orthodox Church of Estonia in Exile was re-registered and on 20 February 1996, Bartholomew I of Constantinople restored the church's position as subordinate to Constantinople, not Moscow. Patriarch Alexy II of Moscow, who had been born in Estonia, rejected this loss of territory, and severed ties with Patriarch Bartholomew on February 23, removing his name from the diptychs. The two sides would then negotiate in Zürich, and a settlement was reached on 16 May 1996. In it, the ethnically Estonian population of Estonia would be under the jurisdiction of the Estonian Apostolic Orthodox Church, while the ethnically Russian population of Estonia would be under the jurisdiction of the Estonian Orthodox Church of the Moscow Patriarchate. After signing the document the Russian Church restored communion with the Ecumenical Patriarchate. The Soviet Union, initially, had a policy of repression against the Orthodox Church, regardless of its denomination. However, after the start of the Nazi Invasion of the Soviet Union, Joseph Stalin transformed the Russian Church into a propaganda tool to intensify patriotic support for the war effort. Following Soviet victory in the war, various autonomous and Independent Orthodox churches around eastern Europe were forcefully integrated or reintegrated into the Russian Church, including the church in Ukraine. Many of the church's leaders at this time were installed and closely monitored by the NKVD to ensure the church's support for the Soviet Union.

This situation led to the rise of rival, anti-Russian and anti-Soviet churches within Ukraine, including the Ukrainian Autocephalous Orthodox Church (UAOC), founded in 1917 which declared itself the restored autonomous church that existed prior to 1686 but had been eradicated within Soviet Ukraine by the 1930s. The church was largely supported by Ukrainian émigrés and diaspora, and was restored as a legally recognised church by the Ukrainian government in 1991. In 1992, the Ukrainian Orthodox Church – Kyiv Patriarchate (UOC-KP) came into existence, being founded by members of the Russian Church defrocked for insubordination, alongside support with the Ukrainian émigré community. The church submitted a request for Ukrainian autocephaly at its founding synod in Kyiv in 1992. These churches were competing with the Ukrainian Orthodox Church (UOC-MP), the Russian Church in Ukraine.

On 11 October 2018, the Holy Synod of the Ecumenical Patriarchate of Constantinople revoked the Russian Church's letter of issue, allowing them to ordain the Metropolitan of Kyiv, re-established a stauropegion in Kyiv, and lifted the Russian Church's excommunication of members of the UAOC and the UOC-KP. In response, on 15 October, the Holy Synod of the Russian Orthodox Church severed all ties with the Ecumenical Patriarchate of Constantinople and barred all members of the Russian Church from receiving communion or sacraments from any churches with ties to the Ecumenical Patriarchate. On 15 December 2018, the UAOC and UOC-KP voted to merge in the Unification council of the Eastern Orthodox churches of Ukraine, forming the restored Orthodox Church of Ukraine, with Epiphanius I of Ukraine, of the UOC-KP, becoming the first primate of the unified church. On 5 January 2019, Bartholomew I signed the official tomos that granted autocephaly to the Orthodox Church of Ukraine.

In addition to severing ties with the Ecumenical Patriarchate, the Russian Church has also severed communion with Archbishop Ieronymos II of Athens primate of the Church of Greece, Patriarch Theodore II of Alexandria, and Archbishop Chrysostomos II of Cyprus. In response to the severing of ties with the Ecumenical Patriarchate, the Archdiocese of Russian Orthodox Churches in Western Europe (AROCWE), voted to dissolve itself, although the vote failed, it resulted in a split in AROCWE, with several churches leaving to form the "Vicariate of Russian Tradition of the Metropolis of France", while , head of the AROCWE, personally joined the Russian Church. After the 2022 Russian invasion of Ukraine, the UOC-MP severed all ties with the Russian Church.

Organisation and leadership

thumb|A timeline showing the main autocephalous Eastern Orthodox churches, from an Eastern Orthodox point of view, up to 2022

alt=|thumb|The [[Canonical territory|canonical territories of the main autocephalous and autonomous Eastern Orthodox jurisdictions as of 2022]]

thumb|[[St. Nicholas Cathedral (Seoul)|St. Nicholas Cathedral in Seoul, Korea]]

The Eastern Orthodox Church is a fellowship of autocephalous (; "self-headed") churches, with the ecumenical patriarch of Constantinople recognised as having primus inter pares status. The patriarch of Constantinople has the honour of primacy, but his title is only first among equals and he has no real authority over churches other than the Constantinopolitan church. Rather, his role is limited to defined prerogatives interpreted by the ecumenical patriarch. At times, though, the office of the ecumenical patriarch has been accused of Constantinopolitan or Eastern papism.

The Eastern Orthodox Church considers Jesus Christ to be the head of the Church and the Church to be his body. It is believed that Church authority and the grace of God is directly passed down to Orthodox bishops and other clergy through the laying on of hands—a practice started by the New Testament apostlesand that this unbroken historical link is an essential element of the true church (; ; ) The Eastern Orthodox Church asserts that apostolic succession requires apostolic faith, and bishops without apostolic faith, who are in heresy, forfeit their claim to apostolic succession.

The Eastern Orthodox communion is organised into several regional churches, which are either autocephalous or lower-ranking autonomous ("self-governing") church bodies unified in theology and worship. These include the fourteen autocephalous churches of the Constantinople, Alexandria, Antioch, Jerusalem, Georgia, Cyprus, Bulgaria, Serbia, Russia, Greece, Poland, Romania, Albania, and the Czech Republic and Slovakia, which were officially invited to the Pan-Orthodox Council of 2016; the Orthodox Church in America formed in 1970; the autocephalous Orthodox Church of Ukraine created in 2019; the Macedonian Orthodox Church – Ohrid Archbishopric, granted autocephaly by the Serbian Orthodox Church in 2022; and a number of autonomous churches.

Other councils have helped to define the Eastern Orthodox position, specifically the Quinisext Council, the Synods of Constantinople, 879–880, 1341, 1347, 1351, 1583, 1819, and 1872, the Synod of Iași, 1642, and the Pan-Orthodox Synod of Jerusalem, 1672; the Pan-Orthodox Council, held in Greece in 2016, was the only such Eastern Orthodox council in modern times.

According to Eastern Orthodox teaching the position of "first among equals" gives no additional power or authority to the bishop that holds it, but rather that this person sits as organisational head of a council of equals (like a president).

One of the decisions made by the First Council of Constantinople (the second ecumenical council, meeting in 381) and supported by later such councils was that the Patriarch of Constantinople should be given equal honour to the Pope of Rome since Constantinople was considered to be the "New Rome". According to the third canon of the second ecumenical council: "Because [Constantinople] is new Rome, the bishop of Constantinople is to enjoy the privileges of honor after the bishop of Rome".

The 28th canon of the fourth ecumenical council clarified this point by stating: "For the Fathers rightly granted privileges to the throne of Old Rome because it was the royal city. And the One Hundred and Fifty most religious Bishops (i.e. the second ecumenical council in 381) actuated by the same consideration, gave equal privileges to the most holy throne of New Rome, justly judging that the city which is honoured with the Sovereignty and the Senate, and enjoys equal privileges with the old imperial Rome, should in ecclesiastical matters also be magnified as she is."

Because of the schism, the Eastern Orthodox no longer recognise the primacy of the pope of Rome. The patriarch of Constantinople therefore, like the Pope before him, now enjoys the title of "first among equals".

Adherents

right|thumb|300px|Distribution of Eastern Orthodoxy in the world by country

The most reliable estimates currently available number Eastern Orthodox adherents at around 220 million, making Eastern Orthodoxy the second largest Christian communion in the world after the Catholic Church.

According to the 2015 Yearbook of International Religious Demography, as of 2010, the Eastern Orthodox population was 4% of the global population, declining from 7.1% in 1910. The study also found a decrease in proportional terms, with Eastern Orthodox Christians making up 12.2% of the world's total Christian population in 2015 compared to 20.4% a century earlier. A 2017 report by the Pew Research Center reached similar figures, noting that Eastern Orthodoxy has seen slower growth and less geographic spread than Catholicism and Protestantism, which were driven by missionary activity across the world.

Over two-thirds of all Eastern Orthodox members are concentrated in Southeast Europe, Eastern Europe and Russia, with significant minorities in Central Asia and the Levant. However, Eastern Orthodoxy has become more globalised over the last century, seeing greater growth in Western Europe, the Americas, and parts of Africa; churches are present in the major cities of most countries. Adherents constitute the largest single religious community in Russia