He was born on 11 March 1884 in Double Bay, Australia, to Jane de Brixton née Price and George Knox.

Knox attended Malvern College in England and entered the Levant Consular Service in early 1906.

[1] In December 1923, Knox moved to Berlin, where he worked for three years before being promoted to acting counsellor in Turkey.

[1] On 1 April 1932, Knox became High Commissioner of the League of Nations at Saar,[2] managing the territories affairs in the face of increasing hostility from Nazi Germany.

His health again forced him to switch roles,[1] and Knox served as Ambassador of the United Kingdom to Brazil from 1939 to 1941,[3] when he retired.