The Bug Cossack army is one of the many "white spots" in Ukraine's military history. The proposed study is based on authentic archival sources, museum materials, statistics, local historians, depicts the heroic and deeply dramatic fate of the Bug Cossacks, who had to endure Tatar raids, wars with Turkey and Napoleonic France, and the arbitrariness of the Russian administration. The "red thread" through the plot of the book is the desire for freedom in the vast majority of unknown heroes, who could not break either the royal fears of the new "Mazepa" or the tyranny of Arakcheev ... The book contains a large appendix, which are documents stored in state archives Kherson and Odessa regions. Most of them have not been published yet. The proposed study is the first book in historiography on the history of the Bug Cossack army.