Began working in newspapers in the 1920s, first for the Glasgow Record and Sunday Mail, joining the Daily Mail in 1923 and transfering to the Daily Mirror in 1926; King was made editorial director of the Sunday Pictorial in 1937, working with Hugh Cudlipp; became chairman of the Mirror Group in 1951, a post he held until 1963; acquired Amalgamated Press in 1958 and then took over the Odhams group, acquiring the Daily Herald (latter renamed the Sun); Mirror Group renamed the International Printing Corporation (IPC) in 1963, with King as chairman; became part-time chairman of the Bank of England in 1965, serving also as a member of the National Coal Board; however, openly criticised Labour Prime Minister Harold Wilson in his newspaper in 1968, and was dismissed by IPC.