Christianity has a long history in Anatolia (Asia Minor) and Armenian Highlands (now part of Turkey), which is the birthplace of numerous Christian Apostles and Saints, such as Paul of Tarsus, Timothy, Nicholas of Myra, Polycarp of Smyrna and many others.
The percentage of Christians in Turkey fell from 19 percent in 1914 to 2.5 percent in 1927, 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. There is also a small group of ethnic Orthodox-Christian Turks (mostly living in Istanbul or Izmir) who follow the Greek Orthodox or Syrian Orthodox church. They are often confused with ethnic Greeks. Some of them actually have a Greek background, but there are ethnic Turks, who never converted to Islam in the history between this population. Currently there are 236 churches open for worship in Turkey. The Eastern Orthodox Church has been headquartered in Istanbul since the 4th century.