Book excerpt: With the research of German-language children's and youth literature and its media associations in the period from 1900 to 1945 as well as the recording of all data in an online portal for research and visual analysis, an innovative contribution to the historiography of children's and youth literature is available. The introduction provides information on the criteria for inclusion, central sources, theoretical frameworks, and the spectrum of the media associations investigated. Part I assembles three overview articles on the media of radio, film and theater for children and young people as well as a contribution on the conception and development of the online portal. In the second part, 18 selected media alliances are presented, sorted into the categories pioneers conquer the new media - stage children migrate to radio and/or film - fairy tales in film and radio - classics in all media - school stories in the theater, book and on the screen - crime and scandal on the screen - political conquers book and film.