Circassians is a broad ethnonym of the Turkic origin, which in Russia, Turkey and Persia used to be, and in the case of Turkey is now, applied to peoples of different ethnicities living on the North Eastern and Eastern shores of the Black Sea, and in the Northern Caucasus.
Prominent Soviet professor of Caucasian studies Volkova wrote:[2]«The origin of the term Circassian, with its ethnical nature coming only from the Turkic roots, was related to some political events of the 13th century.In the Russian letopis of the 16th century, when describing events of 1152, name "Circassians" is mentioned as another name for Turkic vassals of Kievan princes — "Black Klobukhs"[3] — consisting of Turkic tribes of Torks, Pechenegs, Berendei and Kovuy (often identified as Kayi).
[11] Some of the "Asian" Circassians, who defied Mongol or Lithuanian rule, settled around Dnieper river, mixed with Eastern European runaways in the XIV-XV centuries, accepted Christianity and eventually switched to a Slavic language.
In result, in the 15-18th centuries the term was applied by the Russians to Slavic-speaking Cossack population of the Black Sea shores and Dnieper region.
In 1634 a Dominican order monk Giovani Lucca wrote:[19] Circassians look very much like Nogai Tatars...