What is de hadeln?

Some articles on de hadeln:

Visions Du Réel
... The festival was founded by Moritz de Hadeln (who later headed the Locarno International Film Festival, the Berlin International Film Festival, the Venice International Film ... It was not the time television was controlling everything..." ” Moritz de Hadeln directed the festival until 1979, and he assisted Erika when she took over as head of the festival ... years of the Nyon International Documentary Film Festival, Erika de Hadeln negotiated with the film authorities in East Europe and Russia — and worked with documentary film-makers ...