ENUkrainian hetmanate during the National liberation revolution of the 17th century permanently paid much attention to the Belarusian direction, focusing on the border with the Grand Duchy of Lithuania (henceforce - the GDL) considerable military forces, even at the most dramatic situations of the revolution. During the Ukrainian liberating actions Belarus got to geopolitical interests of a hetmanate more often, and the Cossack’s administrative and social device and jurisdiction was extended on its territory. Difficidties for the Ukrainian Cossacks In Belarus were caused by good organized Lithuanian troops and active defensive tactic of Yanush Radzivill. His troops closely came to the Ukrainian border, hi the third week of June, 1651 the plan of military operations nearest the northern Ukrainian borders which was carefully planned by Yanush Radzivill entered a practical phase of realization, and troops of the GDL launched an offensive on the Ukrainian positions. On June 26, 1651 there was the Second fight near Loyev, during which Ukrainian troops under command of the colonel Martyn Nebaba suffered defeat. As well as in the First fight near Loyev (1649) the attack on the back and the flank of the Ukrainian army became a decisive factor in a victory of troops of the GDL. It is indicated disorientation of the Ukrainian command which began to smash the auxiliary 3 000 corps of I. Mirskiy and also let out the main Lithuanian troops of Yanush Radzivill from a field of vision. Generally after a severe defeat near Berestechko (on 18-30 June. 1651), defensive actions against the GDL army near the northern Uh-ainian borders, difficult Second fight near Loyev (on June 26,1651) and the subsequent to itfight for Kiev in the summer of 1651, with simultaneous blossoming of the guerrilla movement, weakened strengths of the opponent and actually saved from destruction the Ukrainian Cossack state.