Storozhenko I. Khmelnytskyi and Zaporozhian Sich of the late 16th – mid-17th centuries (genesis, evolution and reformation of the Sich organizational structure)

Object: Ukrainian cossacks of end XV – middle of the XVII. Aim: genesis and evolution of organizational and ethnic structures of Ukrainian cossacks of end XV – middle of XVII, in particular Zaporizka Sich, and also reformative role of B. Khmel'nytsky in this process. Methods: system approach and system analysis, historic-system, conception of the ethnogenesis, general-historic and scientific methods, in particular imitation design, extrapolation, structural functional and structural comparative analysis. Results: the structural-functional structure of Large Steppe Border of Ukraine is certain, genesis and evolution of organizational structure of Ukrainian cossacks of the second half of XVI and its first Zaporizhka (Bazavlutska) Sich of end of XVІ is reflected – the first half of the XVII. Sphere of the use: scientific, educational.