David Dain was born on 30 October 1940, son of John Gordon Dain and of Joan (née Connop). He was educated at Merchant Taylors’ School and then St John’s College, Oxford; in 1969 he married Susan Kathleen Moss; they had one son and four daughters.

Dain entered the Diplomatic Service in 1963, and his career included: Third, later Second Secretary, Teheran [Iran] and Kabul [Afghanistan] (1964-68); seconded to Cabinet Office (1969-72); First Secretary, Bonn [Germany] (1972-75); Foreign and Commonwealth Office (1975-78); Head of Chancery, Athens [Greece] (1978-81); Counsellor and Deputy High Commissioner, Nicosia [Cyprus] (1981-85); Head of Western European Department, FCO (1985-89); on attachment to Civil Service Selection Board (1989-90); High Commissioner, Cyprus (1990-94); Assistant Under-Secretary of State, then Director, South Asian and South-East Asian Departments, FCO (1994-97); High Commissioner to Pakistan (1997-2000).