This book by the renowned Russian historian, Doctor of Historical Sciences V. Telitsyn, is the first to describe the history of the Spanish Civil War without ideological bias, which fundamentally distinguishes it from similar publications that appeared in the USSR. It is a truthful and unembellished account of Soviet military specialists and advisors fulfilling their patriotic duty abroad, a story of the first actual clash between the Soviet and German military machines, and of the behind-the-scenes maneuvers of politicians hidden behind the tragedy of the Spanish people.