The Mongol invasion of Rus' left the Principality of Kiev in a severely ruined state. Following the invasion, it was now under the formal suzerainty of the Grand Prince of Vladimir-Suzdal, Alexander Nevsky, who in turn was a vassal to the Mongols. After the Battle of Irpen in 1321, Kiev was the object of desire for the Lithuanian Grand Duke Gediminas, and it was incorporated into the Grand Duchy of Lithuania in 1362. The Principality formally existed as a distinct entity until 1471, when it was converted into the Kiev Voivodeship