Witowt or Witold (vĭtˈôft,–ôlt) [key], Lithuanian Vytautas, 1350–1430, grand duke of Lithuania (1401–30). In 1382, Witowt, as well as his father, was imprisoned by Ladislaus Jagiello (see Ladislaus II, king of Poland), his cousin, in a dispute over territorial claims and the title of grand duke. Although his father died in prison, Witowt escaped to take refuge with the order of Teutonic Knights. The cousins were reconciled in 1384, and Witowt received from Jagiello, whom he recognized as grand duke of Lithuania, Russian territory as an appanage. After Jagiello became (1386) king of Poland, Witowt plotted to separate Lithuania from its union with Poland and to assume the title of grand duke. With the help of the Teutonic Knights and Vasily I, prince of Moscow, he secured recognition as master of Lithuania (1392); in 1401 Ladislaus granted Witowt the grand ducal title while remaining his suzerain as king of Poland. Witowt sought to reduce the Tatars of the Golden Horde to vassalage but was defeated by them in 1399. In 1410, at the battle of Tannenberg, Witowt and Ladislaus defeated the Teutonic Knights, who had been threatening Polish-Lithuanian independence.