Turkey has been home to all three great revealed religions--Judaism, Christianity and Islam—for centuries.

99% of Turkey's people today are Muslim, but Istanbul is also the historic seat of the Ecumenical Orthodox Patriarchate and still has a number of active Orthodox Christian churches.

The Roman Catholic church has some churches and activities, as do small groups of Protestants.

The Assyrian Orthodox church, headed by a patriarch resident in Damascus, Syria, has some active churches and monasteries in southeastern Turkey near Mardin.

Turkey's Jewish community has roots in the distant past when Anatolia was the Roman province of Asia (Minor). St Paul was born into a Jewish family in the Roman city of Tarsus on Turkey's eastern Mediterranean coast. But most Turkish Jews trace their antecedents to the influx of Sephardim from Spain and Portugal in the late 15th century. Driven out of their homelands by the Spanish Inquisition, they found refuge and prosperity in the Ottoman Empire.

Because it is in the nature of most every religion to believe that its doctrine—and only its doctrine—is true, and all others are either flawed or downright false, there have been times when believers of different religions did not get along. But in general, Turkey's history of religious tolerance is exemplary.

Under the Ottoman Empire, each religious community was autonomous in domestic affairs and could apply its own religious law in its own courts. The head of each community—the Chief Rabbi (Hahambasi), Orthodox Patriarch, etc.—was responsible to the sultan for the good behavior of his community.

With the coming of ethnic-religious nationalism in the 19th century, this multi-confessional Ottoman modus vivendi was destroyed. The Ottoman system broke down to be replaced by more or less homogeneous ethnic-religious nation states such as Armenia, Bulgaria, Greece and Israel. By the end of the 20th century, many non-Muslim Turkish citizens had emigrated to these or other countries, leaving only small minorities where there once had been large, thriving communities.

Because the Turkish Republic is a staunchly secular state, all religious activity is supervised by the government. Citizens are free to worship as they wish, but proselytization is not permitted.

The heads of the major religious communities—the Chief Mufti, the Chief Rabbi and the Ecumenical Orthodox Patriarch—are officially government employees. Pious endowments (vakif, wakf) are administered by the government, as is all religious real property. Wearing religious garb is permitted in places of worship but prohibited in public areas.