The Oeuvre’s founder and director, Alfred Siegfried (1890-1972), terrorised Traveller children. The Yenish likened him to Hitler. He hunted down Gypsies with the unfailing assistance of the police and the authorities. Bent on "eradicating the evil of nomadism at its source, i.e. the children, by systematic educative measures," he had a pathological hatred of Travellers, whom he referred to as mentally retarded psychopaths.

In Germany, Switzerland, France and Austria there exist so-called white Gypsies who are known under the names of Jenische (German), [Yéniche] fr:Yéniche (French), and Yenish or Yeniche (English). Their language seems to be grammatically identical with other (Swiss) German dialects; the origin of the lexicon, however, incorporates German, Romani, Yiddish and other words.