The story is set in the Dagestani region during the conflict between Russia and Circassia, Dagestan, and Chechnya in the 1850s. And yet I can't seem to find any reference to "Tavlin," "Tavlinia," or anything that I might guess off the top of my head. Help?
The Brockhaus and Efron Encyclopedic Dictionary says that the word Тавлинцы (Tavlinian) was used by Russians, Kumyks, and Georgians for mountaineers of the North Dagestan, mostly Avars.