Kaitag (Mountain Kayı), which for ten centuries (10–19 cc.) was a lingua franca in the North Caucasus, is the Russified name of the Kayı tribe who played a prominent role in the history of the Caucasus. Kaitag principality was a leading component of the Shamkhalate of Kazi-Kumukh state on the Caspian western seaboard that, in different forms, lasted from the 8th to the 19th centuries.