Book excerpt: The downfall of tsarism in 1917 left the peoples of Russia facing an uncertain future. Nowhere were those anxieties felt more than among the Cossacks. The steppe horsemen had famously guarded the empire's frontiers, stampeded demonstrators in its cities, suppressed peasant revolts in the countryside and served as bodyguards to its rulers. Their way of life, intricately bound to the old order, seemed imperiled by the revolution and especially by the Bolshevik seizure of power. Many Cossacks took up arms against the Soviet regime, providing the anticommunist cause with some of its best warriors--as well as its most notorious bandits. This book chronicles their decades-long campaign against the Bolsheviks, from the tumultuous days of the Russian Civil War through the doldrums of foreign exile and finally to their fateful collaboration with the Third Reich.