Wenceslaus I (Czech: V?clav; c. 907  September 28, 935), or Wenceslas I, was the duke (kn??e) of Bohemia from 921 until his assassination in 935, purportedly in a plot by his own brother, Boleslav the Cruel. His martyrdom, and the popularity of several biographies, quickly gave rise to a cult-like following and reputation of superhuman goodness, resulting in his being elevated to Sainthood, posthumously declared king, and seen as the patron saint of the Czech state. He is even the subject of a Christmas carol written in 1853 that remains popular to this day, Good King Wenceslas. The Codex Manesse, Manesse Codex, or Gro?e Heidelberger Liederhandschrift is a Liederhandschrift (medieval songbook), the single most comprehensive source of Middle High German Minnesang poetry, written and illustrated between ca. 1304 when the main part was completed, and ca. 1340 with the addenda. The codex was produced in Z?rich , for the Manesse family.