The paper examines little-known pages of the history of the Ukrainian National Revolution of the mid-17th century. echo of the liberation competitions of the Ukrainian people in socio-political processes in Belarus, clarifies the nature and content of the policy of the hetman governments of B. Khmelnitsky, I. Vigovsky and Yu. Khmelnitsky to solve the "Belarusian problem." Against the historical background of the middle - second half of the XVII century. for the first time, the political and military activities of the Belarusian colonel I. Nechai are fully and comprehensively covered.