Cossack man - who is it?

[Jim McDougall]

As noted, Shamil was the leader of the Sufi Naqshbandi order in their resistance to invading Russian forces in what were often termed 'The Murid Wars' (Murid was the term for disciples in this movement 1829-59).
These campaigns in the eastern Caucusus were part of the larger conflicts there which lasted 1817-64, but Shamil surrendered in 1859.

The book "Sabers of Paradise" is spellbinding! and one of the best accounts describing these complex and colorful times and these warriors, of which Shamil seems almost superhuman!