Kenneth Diplock, Baron Diplock

William John Kenneth Diplock, Baron Diplock, PC (8 December 1907 – 14 October 1985[1]) was a British judge and successively a Justice of the High Court in England and Wales and a Lord Justice of Appeal before being created a Law Lord.[2]

Lord Diplock
Lord of Appeal in Ordinary
In office
30 September 1968  14 October 1985
MonarchElizabeth II
Personal details
Born(1907-12-08)8 December 1907
Died14 October 1985(1985-10-14) (aged 77)

Early life

He was born in Croydon, the second child of Irish solicitor Herbert Diplock and his wife Christine. He attended Whitgift School in Croydon and University College, Oxford, where he read chemistry and graduated with a second-class degree.[3] He later become an Honorary Fellow in 1958.[4]


Diplock was called to the Bar by the Middle Temple in 1932. He left practice in 1939 to serve in the war; in 1941 he joined the Royal Air Force, in which he reached the rank of squadron leader.[3] From 1939 to 1948, he served as secretary to the Master of the Rolls, Lord Greene.[3]

He subsequently returned to practice in 1945; he was made a King's Counsel (KC) in 1948, at the age of 41. In 1956, he was appointed to the High Court.[4]and then promoted the Court of Appeal in 1961.

He became a Lord of Appeal in Ordinary (Law Lord) on 30 September 1968[1] and was elevated as a life peer with the title Baron Diplock, of Wansford in the County of Huntingdon and Peterborough to the House of Lords.[5][6]He became the senior Law Lord upon the retirement of Lord Wilberforce in 1982. He resigned his seniority in October 1984 but remained a Law Lord until his death the following year.

As Lord Diplock, he chaired a commission set up in 1972 to consider legal measures against terrorism in Northern Ireland, which led to the establishment of the juryless Diplock courts with which his name is now often associated.

At the time of his death, Lord Diplock was the longest serving Law Lord.[1]

Personal life

He married Maraget Sarah Atcheson in 1938; they had no children.[7][3]

Contributions to legal thought

He made many contributions to legal thought and pushed the law in new and unique directions, not least UK courts without juries ('Diplock courts)'.[8] His rulings, especially those on administrative law, are often considered as authoritative not only in England but across the Commonwealth and even in the United States, where he has been cited by the Supreme Court.[9][10]

Examples include Council of Civil Service Unions v Minister for the Civil Service [1984] UKHL 9 or R (National Federation of Self-Employed and Small Businesses Ltd) v Inland Revenue Commissioners [1982] A.C. 617, on grounds of review and locus standi respectively.

The current typology of grounds for judicial review is owing to Lord Diplock.

Notable judgments

See also


  1. Dickson, Brice (1989). "The Contribution of Lord Diplock to the General Law of Contract". Oxford Journal of Legal Studies. 9 (4): 441. doi:10.1093/ojls/9.4.441.
  2. Hansard: 7th October 1968
  3. Sedley, Stephen; Quesne, Godfray Le (2004). "Diplock, (William John) Kenneth, Baron Diplock (1907–1985), judge". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/31031. Retrieved 23 September 2020. (Subscription or UK public library membership required.)
  4. Andrews, Neil (2011). Contract Law. Cambridge University Press. p. 681. ISBN 978-0-521-12467-6.
  5. "No. 44687". The London Gazette. 1 October 1968. p. 10537.
  6. name="contract law"
  7. "Diplock, Baron (Life Peer), ((William John) Kenneth Diplock) (8 Dec. 1907–14 Oct. 1985)". WHO'S WHO & WHO WAS WHO. 2007. doi:10.1093/ww/9780199540884.013.u163589. ISBN 978-0-19-954089-1. Retrieved 23 September 2020.
  8. Report of the Commission to Consider Legal Procedures to deal with Terrorist Activities in Northern Ireland (Cmmd. 5185); full text of the Diplock Report
  9. "Jones & Laughlin Steel Corp. v. Pfeifer, 462 U.S. 523 (1983)" (PDF).
  10. "General Electric Co. v. MV Nedlloyd".
  11. Woolf, Harry (1986). "The Role of the English Judiciary in Developing Public Law". William and Mary Law Review. 27 (4): 675.
  12. Laws, John (October 1992). "Is the High Court the Guardian of Fundamental Constitutional Rights". Commonwealth Law Bulletin. 18 (4): 1389. doi:10.1080/03050718.1992.9986233.
  13. Sacks, Vera; Maxwell, Judith (May 1984). "Unnatural Justice for Discriminators". The Modern Law Review. 47 (3): 336–337. JSTOR 1095955.
  14. Jowell, Jeffrey; Lester, Anthony (April 1988). "Beyond Wednesbury: Substantive Principles of Administrative Law". Commonwealth Law Review. 14 (2): 859. doi:10.1080/03050718.1988.9985971.
  15. The Hong Kong Fir [1961] EWCA Civ 7
  16. Moschi v. Lep AirServices Ltd. [1973] A.C. 331 per Lord Diplock, confirmed in Photo Production Ltd. v Securior Transport Ltd. [1980] UKHL 2 at [5] per Lord Wilberforce