[3] Mendl was made a Knight Bachelor in 1924 for services to the Crown, allegedly due to his retrieval of letters from a gigolo who had been blackmailing Prince George, Duke of Kent.

[7] President of the Council of Ministers Pierre Laval believed Mendl was working for British intelligence, blaming him for leaking the Hoare–Laval Pact that would have given much of Ethiopia to fascist Italy.

[3] His connections meant that he was able to invite the socialist Léon Blum to the embassy after his 1936 election, whilst the ambassador George Clerk hadn't met him.

[3] Mendl, along with then ambassador Eric Phipps, supported appeasement, playing down Winston Churchill's importance in March 1938 and trying to prevent Anthony Eden from speaking in Paris in June 1939.

[citation needed] Mendl appeared in Alfred Hitchcock's 1946 film Notorious in the role of Commodore who meets Ingrid Bergman's character at a party.