In various contexts, particularly in the USA, Ernst Keller is referred to in the history of graphic design as the father of the so-called Swiss Style, later known as the International Typographic Style. This recognition is based on the large number of Keller's students who later shaped and popularized this Swiss Style. Keller's contributions are primarily acknowledged through his body of work, especially his poster designs and his involvement with typography and graphics in architecture. However, fundamental to his legacy is Ernst Keller's contribution to the development of innovative, non-academic didactic principles in design education. His teaching activities starting in 1918 can be defined as one of the world's first systematic training programs for graphic design. From his intensive teaching from 1918 to 1956, a diverse range of designers emerged.