LTReikšminiai žodžiai: Abiejų Tautų Respublikos-Maskvos karas, 1654–1667; Privati tvirtovė; Įtvirtintas miestas; Liachavičai; Nesvyžius; Senasis Bichavas; Sluckas. Keywords: Russo-Polish War of 1654–1667; Grand Duchy of Lithuania; Private fortress; Fortified town; Liachavichy; Niesvizh; Old Bychau; Sluck.Reikšminiai žodžiai: Lietuvos Didžioji Kunigaikštystė (LDK; Grand Duchy of Lithuania; GDL); Abiejų Tautų Respublika (ATR; Rzeczpospolita Obojga Narodów; Žečpospolita; Sandrauga; Polish-Lithuanian Commonwealth); 17 amžius; Radvilos (Radziwill; Radvila family); Sapiegos (Sapiega family); Didikai ir magnatai; Karai; Okupacija; 17th century; Wars; Occupation; Magnates.
ENThe article focuses on the fate of private magnates’ fortresses and towns located on the territory of the Grand Duchy of Lithuania, during the great war of the Polish-Lithuanian Commonwealth with Muscovy in 1654–1667. The course of military operations during the conflict showed that only the fortresses surrounded by modern, kept in good condition bastion fortifications, that had strong garrisons consisting at least partly from experienced professional soldiers, equipped with a sufficient artillery, and provided with large supplies of food and war materials could make an effective, long-lasting resistance to the enemy. Unfortunately, extremely poor condition of the GDL treasury, as well as limited financial resources of the state, meant that only the two richest magnates — the Radziwills and Sapiehas could afford such expensive investments. The heroic defense of the Old Bychaŭ and Liachavichy or unbending will of the protectors of Niesvizh and Sluck are, undoubtedly, the most spectacular military successes of the GDL in the years of 1654–1660, when almost the entire territory of Belarus and Lithuania came under Muscovy occupation. [From the publication]