His father, Simon Tanner, was a publisher, printer, and head of several Swiss newspapers, including the Romansh-language Fögl Ladin [de].

[1][2][3] Hermann completed secondary school in Samedan, Graubünden, then went on to study business as well as Latin, Ancient Greek, and a few Slavic languages.

[8] Eventually, Tanner left his position managing his father's firm, to move to Bern, working as a writer and publicist.

A member of the Bernina branch of the Swiss Alpine Club, Tanner was a friend of mountain climber Christian Klucker, writing a pocket guide entitled "Forno-Albigna-Bondasca" with him in 1936.

[9] The guide, described as a monograph in a journal from the Club Alpino Italiano, included work by geologist Christian Tannuzzer and Gaudenz Giovanoli.

Additionally, he was a proponent of various international auxiliary languages, supporting Volapük, Esperanto, Ido and finally Occidental (later Interlingue) at various points.

Tanner was purportedly very confrontational in his support, for example wearing the Ido star to an Esperanto Congress, and later an Occidentalist tilde to an Idist meeting.

[20] He died on 1 September 1961 in Tiefenau [de], Bern, after a period of mental decline and illness, partly due to chronic bone disease.