The Russian invasion on the morning of 24 February became a turning point in the past of the Armed Forces of Ukraine, which had to face the powerful aggressor army. Almost immediately, the universal process of improvement of the armed forces began, first taking into arms a number of volunteers, and then besides mobilized. Thus, the process of fast improvement of the number of SZU began, and consequently besides structural changes, including the improvement of correlated tactical compounds (brigades) of the alleged Reserve Corps and the formation of fresh units - battalions, regiments or brigades.