Koloman Moser (1868–1918), co-founder of the Secession and member of the Wiener Werkstätte, was commissioned by Otto Wagner in 1904 to design the windows for the Church of St. Leopold (also called Otto-Wagner-Church or Church am Steinhof). Architecture and décor in this work culminate to a Gesamtkunstwert, an ideal work of art. The south window “Die Verheißung des Himmels” [The Promise of Heaven] over the entrance of the church, designed by Leopold Forster based on Moser’s composition, thereby radiates a particular charm. The depiction of God the Father, two angels, as well as Adam and Eve is one of the main works of planar art of the reform movement in Vienna around 1900. Koloman Moser was also entrusted with the designs for the altarpiece but this assignment was never executed due to a disagreement with the construction site supervision. The drafts for the east and west window and Moser’s draft for the altar are stored in the MAK Library and Works on Paper Collection together with about further 2 000 objects from this exceptional artist.