Krewo Union of 1385

an agreement for the dynastic union of the Grand Duchy of Lithuania and Poland, under which the Lithuanian Grand Duke Jagiełło, after marrying the Polish Queen Jadwiga, was to be proclaimed king of Poland. The agreement was signed on Aug. 14, 1385, in the castle of Krewo, now in the Byelorussian SSR. Jagietto and his brothers pledged that they and their subjects would adopt Catholicism, unite the lands of the Grand Duchy of Lithuania with Poland, and facilitate the return to Poland of lands it had lost. The union promoted the joint efforts of the Lithuanian, Polish, Russian, Byelorussian, and Ukrainian people in their struggle against the Teutonic Order. The union also served the interests of the Polish feudal lords, who were attempting to seize the Ukrainian, Byelorussian, and Russian lands included in the Grand Duchy of Lithuania, as well as those of the Lithuanian feudal lords, who relied on Polish support to continue their conquest of Russian land.