Viktor Ullmann’s Kaiser von Atlantis</> based on a libretto by Peter Kien, ambiguously termed in the prologue as "a kind of opera", was composed in the ghetto Terezín in 1943/44 and is considered one of the "milestones of intellectual resistance" in Terezín and far beyond. The libretto takes a firm stand on the political situation in life by using the means of a mystery play. In the tradition of the Zeitoper</> (opera of the time) of the 1920s, Ullmann used direct quotations to assign his music the role of political commentator.