Eastern Orthodoxy by country
Based on the numbers of adherents, the Eastern Orthodox Church (also known as Eastern Orthodoxy) is the second largest Christian communion in the world after the Roman Catholic Church. The most common estimates of the number of Eastern Orthodox Christians worldwide is approximately 200–260 million. The numerous Protestant groups in the world, if taken all together, outnumber the Eastern Orthodox, but they differ theologically and do not form a single communion.
Christianity in the Middle East
The percentage of Christians in Turkey fell from 19 percent in 1914 or 3 million (thought to be an undercount by one-third omitting 600000 Armenians, 500000 Greeks and 400000 Assyrians) to 2.5 percent in 1927 in a population of 14 million, due to events which had a significant impact on the country's demographic structure, such as the Armenian Genocide, the population exchange between Greece and Turkey, and the emigration of Christians (such as Levantines, Greeks, Armenians etc.) to foreign countries (mostly in Europe and the Americas) that actually began in the late 19th century and gained pace in the first quarter of the 20th century, especially during World War I and after the Turkish War of Independence. Today there are more than 160,000 people of different Christian denominations, representing less than 0.2 percent of Turkey's population, including an estimated 80,000 Oriental Orthodox, 35,000 Roman Catholics, 18,000 Antiochian Greeks, 5,000 Greek Orthodox and smaller numbers of Protestants (Mostly ethnic Turkish). Currently there are 236 churches open for worship in Turkey. The Eastern Orthodox Church has been headquartered in Istanbul since the 4th century.