Correspondence Between Prince Vasyl-Kostiantyn Ostrozkyi and Kryshtof Radziwill as a Source

The article analyzes the correspondence of Kyiv voivode V.- K. Ostrozkyi to his son-in-law, an influential Lithuanian politician Kryštof Radziwill. This is almost the only relatively complete complex of the prince's correspondence in Ostroh, which, given the trusting relationship between both participants of the correspondence, allows us to reconstruct his inner world. As one might suspect, he significantly contradicted Ostroh's public persona. For the prince, the correct ("old") "world" remained in the past, in the times before the Union of Lublin from the year 1569. Innovations were perceived by Vasyl-Kostiantyn as a challenge to this world, which violated its traditional foundations and consisted of an attack on regionalism, a reduction in the political role of princes, and attempts to change the confessional picture of the newly created state. The prince believed that the policy of the Rzeczpospolita's leadership toward the Moscow state was ill-conceived. Ostrozkyi argued that constant wars with the eastern neighbor reduced the overall potential of Christian civilization in its confrontation with Islamic civilization, especially with the country which at that time embodied its offensive in Europe, the Ottoman Empire. Ostrozkyi appealed to Radziwill with the expectation of finding support in the confrontation with Jan Zajmoyskyi, an extremely influential crown chancellor and hetman in the Polish-Lithuanian Commonwealth. It is no coincidence that the Kyiv voivode focused on issues that might have been of interest to the Lithuanian magnate. In particular, these interests included: the attempts of the crown elite, led by J. Zamoyskyi to ignore the interests of the Lithuanian and Ruthenian nobility, unwillingness to pay due attention to defense issues, insufficient allocation of funds for the repair and construction of castle fortifications. Gradually, the correspondence reflects the problem of interfaith confrontation, which was the result of the growth of counter-reformation processes from the beginning of Sigismund III's rule in the Polish-Lithuanian state. Their main emphasis in Europe was on Protestantism (K. Radziwill represented Calvinism), but in the Polish-Lithuanian Commonwealth, as a result of the Union of Brest in 1596, the Counter-Reformation also acquired anti-Orthodox content. In general, the correspondence of Prince V.-K. Ostrozkyi is a unique source that allows us to reconstruct the main features of the identity of an influential princely stratum, which was significantly influenced by the transformation processes in the Polish-Lithuanian Commonwealth in the second half of the sixteenth and early seventeenth centuries.