In Henri Kamer's long expertise on this mask, dated 9 November 1979, he relates how, when he acquired it, he was told that it had been brought back to Germany by Professor Leo Frobenius at the beginning of this century, but that he was unable to confirm the history. He writes that these masks were called ngil, that is to say "gorilla" - animals that are regarded by the Fang as primordial ancestors and used by the chief secret society of the Fang of Gabon and southern Cameroon, a society which meted out justice. He goes on to say that the mask is one of the most beautiful and important he had ever come across, is very ancient and that the decoration on the sides is rarely found.

Perrois (1979, Pl.100) illustrates (in profile) a mask with extensive damages about the border, of similar form but without the border decoration, collected by Heise in 1899 and now in the Völkerkunde Museum, Leipzig. Perrois (p.98) explains that the ngil played a judiciary role in society, but did not survive the spread of colonisation in Gabon.