ENThe events that led to the emergence of a document called «Militares Livoniensum » reflect the military and political situation in the Eastern European region on the eve of the great ordeal – the Livonian War (1558–1583) and the territorial redistribution of the Baltic region, which occurred during and as a result of the war. But Pasvalys Conflict has its own specific prerequisites and its own political dimension in the quadrilateral: Livonia – GDL – Crown of Poland – Prussian Duchy. «Militares Livoniensum» is in fact the register of the Livonian troops under Pasvalys in September 1557, where the troops of Livonia and the Grand Duchy of Lithuania met in a military demonstration. This document illustrates the military mobilization potential of Livonia in the middle of the 16th century.