Vytautas (Lithuanian: Vytautas Didysis (Polish: Witold Kiejstutowicz, Belarusian: Vitaŭt Vialiki), c. 1350 – October 27, 1430), often styled "the Great",(from XV c. onwards) was one of the most famous rulers of medieval Lithuania. With the title Didysis Kunigaikštis, the equivalent of king, he was the supreme ruler of his dominions and also a member of the Order of the Dragon.
Vytautas was the ruler (1401–1430) of the Grand Duchy of Lithuania which chiefly encompassed the Lithuanians and Ruthenians. He was also the Prince of Hrodna (1370–1382) and the Prince of Lutsk (1387–1389), postulated king of Hussites. In modern Lithuania, Vytautas is revered as a national hero and was an important figure in the national rebirth in the early 20th century. Vytautas is a popular male given name in Lithuania. Vytautas Magnus University was named after him. Monuments in his honor were built in many towns in the independent Republic of Lithuania during the interwar period, 1918-1939.