To prevent Russia from being attacked by the Golden Horde, Vasili I entered into alliance with Lithuania in 1392, which turned out to be fragile, since Prince Vytautas (Vitovt) would later capture Vyazma and Smolensk in 1403--1404.
To prevent Russia from being attacked by the Golden Horde, Vasiliy I entered into alliance with Lithuania in 1392 and married Sophia, the only daughter of Vytautas the Great. The alliance turned out to be fragile, since Vytautas would later capture Vyazma and Smolensk in 1403--1404.