Johnson was born in London on 26 March 1930. He was the only son of Lt.-Col.
Sir John Paley Johnson, 6th Baronet and the former Carol Louise Glorney Haas. From his parents marriage, he had one sibling, Wanda Helene Paley Johnson. His parents divorced in 1939 and his father remarried to
Jasmine Lydia Bligh (daughter of Lt.-Col. Hon. Noel Gervase Bligh and granddaughter of
Ivo Bligh, 8th Earl of Darnley), with whom he had another daughter, Sarah Jack Paley Johnson, Peter's younger half-sister. They divorced in 1947 and he married Joan Rosemary Cohen, daughter of Maj. Arthur Cohen, on 27 September 1949. His maternal grandfather was Edmund Haas of New York, and his paternal grandparents were Captain Robert Warren Johnson (son of Vice Admiral John Ormsby Johnson and grandson of
Charles Christopher Johnson) and Grace Isobel Paley (a daughter of barrister Algernon Herbert Paley). He was educated at
Wellington College, Berkshire and at the
Royal Military College of Science. ==Career==