John Sankey was born 8 June 1930. He was educated at Cardinal Vaughan School, Kensington, and Peterhouse College, University of Cambridge, later studying at the University of Leeds (PhD 2002). In 1958 he married Gwendoline Putman, having two sons and two daughters.
After his National Service in 1st (Singapore) Regiment, RA (2nd Lieutenant), in 1952, Sankey entered the Colonial Office in 1953. His career included: Colonial Office, 1953-61; UK Mission to United Nations, 1961-64; Foreign Office, 1964-68; Guyana, 1968-71; Singapore, 1971-73; NATO Defence College, Rome [Italy], 1973; Malta, 1973-75; The Hague, 1975-79 (Governor, British School in the Netherlands); Foreign and Commonwealth Office, Head of Central African Department, 1979-82; High Commissioner, Tanzania, 1982-85; UK Permanent Representative to United Nations Office, Geneva [Switzerland], 1985-90.