David Logan was born 11 Aug 1943, the son of Captain Brian Ewen Weldon Logan, RN (Retd) and Mary Logan (née Fass). He was educated at Charterhouse and University College, University of Oxford, and in 1967 married Judith Margaret Walton Cole, having one son and one daughter (and one son deceased).

Logan entered the Foreign Office in 1965 and during his diplomatic career served in the following posts: Istanbul, Ankara and Foreign and Commonwealth Office, 1965-70; Private Secretary to Parliamentary Under Secretary of State for Foreign and Commonwealth Affairs [Anthony Royle], 1970-73; First Secretary, 1972; UK Mission to United Nations, 1973-77; FCO, 1977-82; Counsellor, Head of Chancery and Consul-General, Oslo [Norway], 1982-86; Head of Personnel Operations Department, FCO, 1986-88; Senior Associate Member, St Antony’s College, University of Oxford, 1988-89; Minister and Deputy Head of Mission, Moscow [Soviet Union], 1989-92; Assistant Under Secretary of State (Central and Eastern Europe), 1992-94, (Defence Policy), 1994-95, FCO; Minister, Washington [United States], 1995-97; Ambassador to Turkey, 1997-2001. Following his retirement from the Diplomatic Service, Logan became Director of the Centre for Studies in Security and Diplomacy, and Hon. Professor, School of Social Sciences, University of Birmingham, 2002-06.