An artist died of pneumonia before he could complete a painting of some of these people taking an oath beneath a linden tree.
A hotel and art venue called these people's "bazaar" commissioned a large painting that imagines an international meeting of composers from it. In a painting, a person from this group stands beneath a billowing red flag as he delivers a sermon from atop a makeshift pulpit. An artist died of pneumonia before he could complete a painting of some of these people taking an oath beneath a linden tree. Christ stands behind an enormous, exultant man holding on to a flowery wreath in each of his outstretched hands in a painting titled for this group's (*) "apotheosis." Two youths of this group crouch next to a sickle in a painting set in their "original homeland." Charles Richard Crane sponsored an Art Nouveau artist to create series of twenty history paintings about this group, including The Celebration of Svantovit. For 10 points, identify this ethno-linguistic group, the subject of an Epic by Alfons Mucha.
A hotel and art venue called these people's "bazaar" commissioned a large painting that imagines an international meeting of composers from it.
Slavs [accept The Slavic Composers or The Slav Epic or Slavic people; accept Czechs or Wends specifically, but every other Slavic group is specifically wrong]