This is the first monograph dedicated to the most interesting phenomenon of the Great War - detachments of special importance that performed sabotage work. The book presents unique materials related to the organization and activities of these formations during 1915-1918. The focus is on the history and everyday life of the largest and most famous partisan unit - the equestrian detachment of ataman Leonid Lunin, whose fame thundered on all fronts. This was the only special forces formation that lasted until 1918 inclusive, avoiding the reforms of A.I. Kerensky and disbandment in October 1917.