William John Kenneth Diplock, Baron Diplock, (8 December 1907 – 14 October 1985) was a British barrister and judge who served as a lord of appeal in ordinary between 1968 and until his death in 1985. Appointed to the English High Court in 1956 and the

Court of Appeal An appellate court, commonly called a court of appeal(s), appeal court, court of second instance or second instance court, is any court of law that is empowered to Hearing (law), hear a Legal case, case upon appeal from a trial court or other ...

five years later, Diplock made important contributions to the development of constitutional and public law as well as many other legal fields. A frequent choice for governmental inquiries, he is also remembered for proposing the creation of the eponymous juryless Diplock courts. Of him, Lord Rawlinson of Ewell wrote that "to his generation Diplock was the quintessential man of the law".

Early life and legal career

Kenneth Diplock was born in South Croydon, the son of solicitor William John Hubert Diplock and his wife Christine Joan (nee Brooke). He was educated at Whitgift School in

Croydon Croydon is a large town in South London, England, south of Charing Cross. Part of the London Borough of Croydon, a Districts of England, local government district of Greater London; it is one of the largest commercial districts in Greater Lond ...

and University College, Oxford, where he read chemistry and graduated with a second-class degree in 1929. He was Secretary of the Oxford Union for a term in 1929. He later become an honorary fellow of University College in 1958. Diplock was called to the bar by the

Middle Temple The Honourable Society of the Middle Temple, commonly known simply as Middle Temple, is one of the four Inns of Court entitled to Call to the bar, call their members to the English Bar as barristers, the others being the Inner Temple (with whi ...

in 1932. After two years in the chambers of Sir Valentine Holmes, KC, he transferred to the chambers of Sir Leslie Scott, KC. In 1939, he left legal practice for service in the Second World War; in 1941, he joined the

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

, in which he reached the rank of squadron leader. From 1939 to 1948, he was secretary to the Master of the Rolls, Lord Greene. Returning to the bar in 1945, Diplock was made a

King's Counsel A King's Counsel (Post-nominal letters, post-nominal initials KC) is a senior lawyer appointed by the monarch (or their Viceroy, viceregal representative) of some Commonwealth realms as a "Counsel learned in the law". When the reigning monarc ...

in 1948, at the early age of 41. He acquired a large practice in commercial work and in advisory work for Commonwealth governments. He was Recorder of Oxford from 1951 to 1956, and served on the Law Reform Committee.

Judicial career

In 1956, Diplock was appointed to the

High Court of Justice The High Court of Justice in London, known properly as His Majesty's High Court of Justice in England, together with the Court of Appeal (England and Wales), Court of Appeal and the Crown Court, are the Courts of England and Wales, Senior Cour ...

, receiving the customary knighthood. Assigned to the Queen's Bench Division, he was appointed President of the Restrictive Practices Court in January 1961. He was promoted to Lord Justice of Appeal in October 1961, and was sworn of the Privy Council. He was chairman of the Security Commission from 1971 to 1982. He became a Lord of Appeal in Ordinary on 30 September 1968 and was elevated as a

life peer In the United Kingdom, life peers are appointed members of the peerage whose titles cannot be inherited, in contrast to hereditary peers. Life peers are appointed by the monarch on the advice of the prime minister. With the exception of the D ...

with the title Baron Diplock, ''of Wansford in the County of Huntingdon and Peterborough'' to the

House of Lords The House of Lords is the upper house of the Parliament of the United Kingdom. Like the lower house, the House of Commons of the United Kingdom, House of Commons, it meets in the Palace of Westminster in London, England. One of the oldest ext ...

. 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 Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war aga ...

in Northern Ireland, which led to the establishment of the juryless Diplock courts with which his name is now often associated. In September 1985, Lord Diplock sat as a judge for the last time, in a special sitting of the Judicial Committee of the Privy Council during the Long Vacation for an urgent civil case from Trinidad and Tobago. Severely ill from emphysema, Diplock came to court from the hospital in a wheelchair and with an oxygen cylinder. At the time of his death, Lord Diplock was the longest serving law lord as well as the last serving superior judge to not be covered by the mandatory retirement age of 75 introduced by the Judicial Pensions Act 1959.

Personal life

He married Margaret Sarah Atcheson in 1938; they had no children.

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)'.Report of the Commission to Consider Legal Procedures to deal with Terrorist Activities in Northern Ireland
( Cmmd. 5185); full text of the Diplock Report 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 In most legal jurisdictions, a supreme court, also known as a court of last resort, apex court, high (or final) court of appeal, and court of final appeal, is the highest court within the hierarchy of courts. Broadly speaking, the decisions of ...

. Examples include '' Council of Civil Service Unions v Minister for the Civil Service'' 984UKHL 9 or '' R (National Federation of Self-Employed and Small Businesses Ltd) v Inland Revenue Commissioners'' 982AC 617, on grounds of review and locus standi respectively. He also made important contributions to contract law. The current typology of grounds for judicial review is owing to Lord Diplock. *Procedural impropriety *'' Nemo judex'' (Bias rule) *'' Audi alteram partem'' (Hearing rule) *Illegality *'' Ultra vires'' *Simple ''ultra vires'' *Extended ''ultra vires'' *Procedural ''ultra vires'' *Fettering *Irrationality * Wednesbury irrationality *Lack of proportionality * Innominate Terms * Primary and Secondary ObligationsMoschi v. Lep AirServices Ltd. 973A.C. 331 per Lord Diplock, confirmed in Photo Production Ltd. v Securior Transport Ltd. 980UKHL 2 at per Lord Wilberforce

Notable judgments

High Court

* '' Silkin v Beaverbrook Newspapers Ltd''

958 Year 958 (Roman numerals, CMLVIII) was a common year starting on Friday of the Julian calendar. Events By place Byzantine Empire * October / November – Battle of Raban: The Byzantine Empire, Byzantines under John I Tzimiskes, Jo ...

1 WLR 743