Wenceslaus I, Duke of Bohemia
https://en.wikipedia.org/wiki/Wenceslaus_I,_Duke_of_Bohemia
(Saint) Wenceslaus I (Czech: Václav [ˈvaːtslaf] (About this soundlisten); c. 907 – September 28, 935), Wenceslas I or Václav the Good[1] was the duke (kníže) of Bohemia from 921 until his assassination in 935. His younger brother, Boleslaus the Cruel, was complicit in the murder.
His martyrdom and the popularity of several biographies gave rise to a reputation for heroic virtue that resulted in his elevation to sainthood. He was posthumously declared to be a king and came to be seen as the patron saint of the Czech state. He is the subject of the well-known "Good King Wenceslas", a carol for Saint Stephen's Day.