Hetman is a political title, historically assigned to military commanders. It was the title of the second-highest military commander (after the monarch) in 15th- to 18th-century Poland and the Grand Duchy of Lithuania, which together, from 1569 to 1795, comprised the Polish–Lithuanian Commonwealth, or Rzeczpospolita. For much of the history of the Principality of Moldavia, the Hetman (Rmn. hatman) was the second in rank in the army after the ruling prince (who held the position of Voivode). Hetman was also the highest military office in Ukraine's Hetmanates, the Zaporizhian Host (1649–1764) and Ukrainian State (1918). The title (гетьман) was used by Ukraine's Cossacks from the 16th century, and by the Czechs (hejtman) in Bohemia from the Hussite Wars (15th century) on. Hejtman is today the term for the elected governor of a Czech region (kraj).