[2] After Eton and Trinity College, Oxford, Mayall joined the Foreign Office and was promoted to Third Secretary in 1940.
[4] From 1940 to 1965, he was en poste in British Embassies in Switzerland, Egypt, France, Japan, Portugal and Ethiopia as well as serving stints in the UK.
He served as Vice-Marshal of the Diplomatic Corps between 1965 and 1972, and was invested as a Knight Commander of the Royal Victorian Order in recognition of his services.
In 1940, Mayall married Renee Eileen, daughter of Sir (Roland) Clive Wallace Burn, K.C.V.O.
Robin Francis Campbell, D.S.O., and daughter of William Ormsby-Gore, 4th Baron Harlech by his wife Lady Beatrice Edith Mildred Gascoyne-Cecil.