ISTANBUL, Nov 24, 2025 (BSS/AFP) - Turkey's Christian community, which hosts Pope Leo XIV this week, was a minority under the Ottoman Empire whose numbers have dwindled due to forced exiles and massacres.

Today, it counts around 100,000 members spread across five denominations -- just a fraction of Turkey's population of 86 million, the vast majority of whom are Sunni Muslim.

Most live in Istanbul or in western Turkey.

National identity cards have not specified religion since 2016, so the only figures available are those provided by the communities themselves, according to Samim Akgonul, a historian, religious minorities expert and head of Turkish studies at Strasbourg University in France.

Here is a brief overview of Turkey's main Christian communities:

- Armenians -

Armenians who hold Turkish citizenship are the largest community with around 50,000 members, although there are "without doubt" a similar number of Armenians in Turkey irregularly either looking for work or just passing through, Akgonul said.

Now predominantly in Istanbul, the community was targeted in a series of organised massacres in 1915, which has been qualified as genocide by around 30 countries, including the United States, France and Germany.

Estimates say Ottoman troops killed between 1.2 million and 1.5 million Armenians.

Turkey, which emerged following the Ottoman Empire's collapse in 1918, has recognised such "massacres" but rejects the term "genocide", pointing instead to civil war and famine in Anatolia.

It puts the number of Armenian deaths between 300,000 and 500,000 and says just as many Turks died.

- Greek Orthodox -

There are around 8,000 Greek Orthodox people in Turkey.

Approximately 3,000 are Greek-speaking Rum Orthodox, and around 5,000 are Arabic-speaking Orthodox. The latter group originated from Hatay and the ancient city of Antioch in the southeast, but now resides in the west.

Largely based in the northwestern Thrace region, around Izmir in the west and Adana in the south, this cohort fell significantly in numbers after Turkey's foundation in 1923, and in 1930.

In January 1923, Greece and Turkey signed the Convention on the Exchange of Populations, which involved a compulsory population exchange based on religion and forced two million people to leave their homes.

Signed nine months before Turkish independence, the convention was promoted by the League of Nations -- the forerunner of the United Nations -- as a "stability guarantee", Akgonul explained.

Further waves of anti-Greek pogroms linked to the Cyprus question came in 1955 and 1964, pushing even more Greek Orthodox to leave.

- Catholics -

Around 25,000 members belong to various Catholic denominations and are located mainly between Istanbul and Izmir.

These are predominantly Levantine populations who settled in the Ottoman Empire in the 17th century, or Armenians who converted to Catholicism in the 19th century as a way to benefit from French protection.

- Protestants -

There are around 15,000 Protestants scattered across the country in the east and southeast. Some are Armenians while others are Muslim converts.

- Assyrian-Chaldean Christians -

Around 25,000 Assyrian or Syriac Christians who claim affiliation with the Syriac Orthodox Church of Antioch, whose patriarchate was based in the southeastern city of Mardin until 1933. It subsequently moved to Homs in Syria, and then Damascus.

The Chaldeans, who count roughly 50 families and mostly live in Istanbul, have very similar rites to the Assyrian church but with one crucial difference: they belong to the Eastern Catholic Church.

Like the Armenians, the Assyrian-Chaldean community is seeking recognition for the mass killings of some 250,000 of their people in 1915, which it wants recognised as genocide.

On October 15, 2023, hundreds of people attended the consecration of Istanbul's Mor Ephrem Syriac Orthodox Church -- the first church built in Turkey since it became a republic 102 years ago.

The pope will visit Mor Ephrem on November 29, where he will meet with local church leaders.