Vitaŭt (also Vytautas, Witold; 1350-1430), Duke of Troki and Horadnia, after 1392 Grand Duke of the Grand Duchy of Lithuania (GDL), outstanding statesman, and military leader. His father, Grand Duke Kiejstut, was killed (1382) at the order of Grand Duke Jahajła, Kiejstut's nephew, in the struggle for power. Challenging his cousin Grand Duke Jahajła, who was made king of Poland in 1386, Vitaŭt allied himself with the Teutonic Order and the Muscovite Grand Duke Vasil I by letting him marry his daughter. In 1392, however, Vitaŭt reached an understanding with King Jahajła, was recognized by the latter as the ruler of the GDL with the title of Grand Duke, and successfully consolidated his power. Vitaŭt fought with Moscow for the control of Smalensk and Novgorod, and added the former city to his state in 1395. In his dealings with the Golden Horde, he lost badly at the Battle of Vorskła (1399). The debacle forced him to seek further accommodation with Jahajła, especially in the face of continuing attacks against the GDL by the Teutonic Order. Soon, Poland and the GDL were brought closer together by the Vilnia-Radom Union of 1401, by which the Polish side pledged not to elect a king without concurrence of lords of the GDL. The act reconfirmed Grand Duke Vitaŭt in his position as the ruler of the GDL, while King Jahajła remained supreme sovereign of the united realm. The 1401 union laid the foundation for a common defense against outside aggression and led to the defeat of the Teutonic Order at the Battle of Grunwald (1410).
Grand Duke Vitaŭt continued consolidating his power in the duchy. Appreciating the role of religion in his eastward territorial expansion, Vitaŭt established an independent Orthodox metropolitanate for the GDL in the city of Navahradak. To enhance his stature as an independent ruler, he attempted in 1429 and 1430 to receive the royal title from the pope but was prevented by Polish efforts. The GDL reached the peak of its power under Vitaŭt, who earned himself the sobriquet "Great" from some historians.
