ENThe article is devoted to the little-explored aspects related to the role of the Lithuanian princes of the Gediminas dynasty in the spread of early firearms. The focus is on its appearance not only on the subservient to Lithuania Russian territories, but also in the lands of the North-East and North-West Rus. The author notes that, thanks to the active political contacts of princes-Gediminians with the Teutonic Order in Prussia, they were able to get the most advanced at that time military-technical means, which made it possible to improve the Russian martial art. Later they had developed the necessary tactics for the effective use of a new barrel of gunpowder weapons in the struggle not only with the fortifications of the Crusaders, but also with the field clashes with the Tartars (the Battle of the Vorskla River in 1399). And although the early guns have not always been able to positively affect the outcome of the last, but they quickly made significant changes in the construction of fortifications in many Russian lands in the studied period.