Historically, the term "Greek Orthodox" has also been used to describe all Eastern Orthodox Churches in general, since "Greek" in "Greek Orthodox" can refer to the heritage of the Byzantine Empire. During the first eight centuries of Christian history, most major intellectual, cultural, and social developments in the Christian Church took place within the Empire or in the sphere of its influence, where the Greek language was widely spoken and used for most theological writings. Over time, most parts of the liturgy, traditions, and practices of the church of Constantinople were adopted by all, and still provide the basic patterns of contemporary Orthodoxy. Thus, the Eastern Church came to be called "Greek" Orthodox in the same way that the Western Church is called "Roman" Catholic. However, the appellation "Greek" was abandoned by the Slavic and other Eastern Orthodox churches in connection with their peoples' national awakenings, from as early as the 10th century A.D. Thus, today it is generally only those churches that are most closely tied to Greek or Byzantine culture that are called "Greek Orthodox".
The Greek Orthodox churches are descended from churches which the Apostles founded in the Balkans and the Middle East during the first century A.D., and they maintain many traditions practiced in the ancient Church. Orthodox Churches, unlike the Catholic Church, have no single Supreme Pontiff, or Bishop (see also: Pontifex maximus), and hold the belief that Christ is the head of the Church. However, they are each governed by a committee of Bishops, called the Holy Synod, with one central Bishop holding the honorary title of "first among equals".
There are also many Greek Orthodox Christians, with origins dating back to the Byzantine and Ottoman periods, who are of Arabic-speaking or mixed Greek and Arabic-speaking ancestry and live in southern Turkey, Israel, Palestine, Iraq, Syria, Lebanon, Jordan, and Egypt. They attend churches which conduct their services in Arabic, the common language of most Greek Orthodox believers in the Levant, while at the same time maintaining elements of the Byzantine Greek cultural tradition.
^Sally Bruyneel; Alan G. Padgett (2003). Introducing Christianity. Orbis Books. p. 7. ISBN978-1-60833-134-5. Retrieved 2 September 2013. The Eastern Orthodox and the Roman Catholic Churches are the oldest with roots going back to the earliest Christian groups.
^Robert L. Plummer (6 March 2012). Journeys of Faith: Evangelicalism, Eastern Orthodoxy, Catholicism and Anglicanism. Zondervan. p. 128. ISBN978-0-310-41671-5. Retrieved 2 September 2013. Catholicism holds that if a Church claims to be Christian, then it must be able to show that its leaders-its bishops and its presbyters (or priests)- are successors of the apostles. That is why the Catholic Church accepts Eastern Orthodox ordinations and sacraments as valid, even though Eastern Orthodoxy is not in full communion with Rome.
^William A. Dyrness; Veli-Matti Kärkkäinen (25 September 2009). Global Dictionary of Theology: A Resource for the Worldwide Church. InterVarsity Press. p. 244. ISBN978-0-8308-7811-6. Retrieved 2 September 2013. This connection is apparent through the historical succession of bishops of churches in a particular geographic locale and by fidelity to the teachings of the apostles (cf. Acts 2:42) and life as it developed in the patristic tradition and was articulated by the seven ecumenical councils.
^Heidi Campbell (22 March 2010). When Religion Meets New Media. Routledge. p. 13. ISBN978-0-203-69537-1. Retrieved 2 September 2013. There are three branches within Christianity: Catholic, Eastern Orthodox, and Protestant. ... The Christian church draws its lineage and roots from the time of Jesus Christ and the apostles in CE 25–30 and the birth of the Church at Pentecost in ...
^The Greek Orthodox Archdiocese of America should not be confused with the Orthodox Church in America, whose autocephaly – granted by the Russian Orthodox Church – is not recognized by the Ecumenical Patriarchate of Constantinople and many other churches of the Eastern Orthodox Communion.
^Roudometof, Victor (2002). Collective memory, national identity, and ethnic conflict. Greenwood Press. p. 179. the only remaining issues between the two sides concern the extent to which minority members should have equal rights with the rest of the Albanian citizens as well as issues of property and ecclesiastical autonomy for the Greek Orthodox Church of Albania.
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Hussey, Joan Mervyn. The orthodox church in the Byzantine empire (Oxford University Press, 2010) online
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