Called to the Bar in 1903, he was in Norway in 1905, when the country gained independence, and he learned Norwegian as well as some Danish and Icelandic.
In 1910 he travelled with Hesketh Hesketh-Prichard from Nain, Newfoundland and Labrador, to Indian House Lake on George River, and contributed a chapter on fishing to Prichard's Through trackless Labrador (1911).
[3][4] Gathorne-Hardy lost a foot in the First World War, where he was mentioned in despatches and awarded the Military Cross and the Croix de Guerre (Belgium).
[2] He was a founding member of Chatham House and, with Lionel Curtis, Honorary Secretary from 1922.
[1] In World War II "he worked on Norwegian propaganda and acted as an unofficial delegate to the Norwegian government in exile", later receiving the Order of St Olaf and an honorary PhD from the University of Oslo.