Six Armenian vilayets
The Six vilayets or Six provinces (Ottoman Turkish: ولايت سته Vilâyat-ı Sitte) or the Six Armenian vilayets (Armenian: Վեց հայկական վիլայեթներ Vets' haykakan vilayet'ner, Turkish: Altı vilayet, Altı Ermeni ili) were the Armenian-populated vilayets (provinces) of the Ottoman Empire:
The term Six Armenian provinces was first used in the Congress of Berlin in 1878.
1including Qizilbash
2including Zaza
3Assyrians (Nestorians, Jacobites, Chaldeans), Circassians, Greeks, Yazidis, Persians, Lazs, Roma
Note: The Ottoman population statistics doesn't give information for separate Muslim ethnic groups such as the Turks, Kurds, Circassians, etc.
Most modern Western scholars agree that the official Ottoman population statistics of 1914 that were based on an earlier census underestimated the number of ethnic minorities, including the number of Armenians. The Ottoman figures didn't define any ethnic groups, only religious ones. So Armenian meant an adherent of Armenian Apostolic Church. Ethnic Armenians who claimed to be Muslims were counted as Muslims, Armenian Protestants - like Pontic Greeks, Caucasus Greeks, and Laz - were counted as others.
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Wikipedia