In 1932 he took part in the first Swiss expedition to the Caucasus with a ski club from Zurich and contributed reports and photographs to the press.

The following year he intended joining five Russian friends, Georgi Charlampiew, Michail Dadiomow, Leonid Gutman, the sculptor Yevgeniy Abalakov and his brother Vitaly on a geological expedition to climb the 7546-meter high Mustagh Ata in China.

Khan Tengri is the world's most northern 7000-meter peak, notable because it has a shorter climbing season, generally more severe weather and thinner air.

They reached the summit on 5 September, but on the descent through a snowstorm Gutman fell and was badly injured and all of the climbers suffered from severe frostbite.

Preserving his legacy, which she viewed as a counterpoint to Switzerland's insular neutrality, became, for Schwarzenbach, both a personal and ideological obligation.

While researching for a new edition of Schwarzenbach's book the writers Robert Steiner and Emil Zopfi came across Saladin's photo archive in Moscow.