Born circa 1338; died Mar. 14, 1391. Ban (viceroy) of Bosnia from 1353 and king from 1377. Member of the Kotromanic dynasty.
In 1366–67, with the help of the Hungarians, Tvrtko put an end to the internecine strife of the Bosnian feudal lords. He then seized part of the Serbian lands. His troops defeated the Turks at Bélica in 1388 and fought in the battle of Kosovo Polje in 1389. After 1389, Tvrtko annexed Dalmatia (with the exception of Dubrovnik) and part of Croatia to Bosnia.