Bourne's great-grandfather, the Conservative politician Hugh Cairns, had served as Lord Chancellor under Benjamin Disraeli.
[citation needed] During the Second World War, Bourne served with the Rifle Brigade in North Africa, Italy, Normandy and north-west Europe.
He was demobilised in 1945 and returned to the University of Oxford to read Jurisprudence, in which he obtained another First, and was awarded the Eldon Law Scholarship.
[1] Bourne entered the British Civil Service in 1956, joining the Lord Chancellor's Department, and later became Principal Assistant Solicitor (1970-1972) and Deputy Secretary (1972-1977).
[1] In 1977 Bourne was appointed Permanent Secretary to the Lord Chancellor's Office and Clerk of the Crown in Chancery and held both positions until his retirement in 1982.