The Grand Duchy of Moscow and Lithuania had fought each other since the reign of Gediminas, who defeated a coalition of Ruthenian princes in the Battle on the Irpin River and seized Kyiv, the former capital of Kievan Rus'. By the mid-14th century, an expanding Lithuania had absorbed Chernihiv and Severia. Algirdas, the successor of Gediminas, allied with the Principality of Tver and undertook three expeditions against Moscow, attempting to take advantage of the youth of the Grand Prince of Moscow, Dmitry Ivanovich, who nevertheless succeeded in fending off these encroachments.