He was the interpreter and translator for Field Marshal Sir Bernard Montgomery, commander of the Anglo-Canadian 21st Army Group, at the German surrender at Lüneburg Heath in Germany on 3 May 1945.

[1] Knee attended Cheltenham Grammar School where his father was the headmaster and he spent a summer with a family in Germany which helped him to become fluent in the language.

[citation needed] His language skills led to postings to a course on the interrogation of Prisoners of War and to a censorship unit in London.

[citation needed] After D-Day he served at Second Army Headquarters under General Miles Dempsey, identifying German units and estimating their strengths.

Upon his return to his studies at Cambridge University Knee switched to an Economics course and he became assistant general secretary at the International Association of Department Stores in Paris and Geneva.