Apostolic Exarchate of Turkey of Europe

The Greek Catholic Apostolic Exarchate of Istanbul (or of Constantinople) ( Exarchatus Apostolicus Constantinopolitanus) is the senior of two missionary pre-diocesan Eastern Catholic jurisdictions that constitute the Greek Byzantine Catholic Church, an Eastern Catholic Church of the Byzantine Rite in Greek language.

It is exempt, i.e. directly subject to the Holy See, not part of any ecclesiastical province (which don't exist in the Greek Catholic Church, as it lacks a Metropolitan). The Apostolic Exarchate covers all territory of Turkey. Its cathedral episcopal see is the Ayatriada Rum Katoliki Kilise (Holy Trinity Rum Catholic Church) in Istanbul. As of 2013, it was the sole parish of the exarchate and has 20 parishioners.

The first steps toward creating a particular jurisdiction for Greek Catholics of the Byzantine Rite in the European part of Ottoman Empire were made in 1907, when Greek Catholic priest Isaias Papadopoulos was made vicar general for the Greek Catholics within the jurisdiction of Apostolic Delegation of Constantinople.

The Greek Catholic Apostolic Exarchate of Constantinople (Istanbul) was founded on June 11, 1911, as the Greek Catholic Apostolic Exarchate of European Turkey. At the same time, on June 28 (1911), Isaias Papadopoulos was appointed titular bishop of Gratianopolis, and he was also entrusted with the initial organization of the newly formed Exarchate, but he was not appointed apostolic exarch. That question had to be postponed because of the breakout of Balkan Wars (1912-1913) when Ottoman Empire lost most of its European territory, and the consequent breakout of First World War (1914-1918). The first apostolic exarch, George Calavassy, was appointed only after the war, in 1920.

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