The Nepalese hills are populated by tribal societies which were neither Buddhist nor Hindu at the outset. The best known are the Magars, the Gurungs, the Tamangs, the Rais and the Lumbus. These masks, some of which were probably linked to the ongoing practice of shamanism, have been used for centuries. They take the form of ancestral faces, mythical figures, demons and buffoons and express the imprint of shamanism and ancestral beliefs on these tribal societies' everyday life and rituals.

But these masks have not been thoroughly researched and are not yet widely known. They started to emerge on the global scene about thirty years ago and have seduced a small number of enthusiasts by their brutal strangeness. One of them was Marc Petit, who started collecting them and became one of the first to understand that their brutality was the result of a very clever art form. He donated some exceptional pieces to the musée du quai Branly.