Robin Cooke, Baron Cooke of Thorndon

Lord Cooke took what could be considered a natural law approach to public law, often seeking to assert a right for the courts to intervene where none was prescribed in legislation. In Fraser v State Services Commission he famously made the comment that "it is arguable that some common law rights may go so deep that even Parliament cannot be accepted by the Courts to have destroyed them." This view contradicted the dominant parliamentary supremacy theories of A. V. Dicey, which had guided common law courts since the late 19th century. However, Cooke's position recalled a similar opinion expressed by the famous 17th century English jurist, Sir Edward Coke.

Lord Cooke's often bold views occasionally drew criticism. In one noteworthy example, some of Australia's most senior judges co-wrote the Preface of Meagher, Gummow and Lehane’s Equity, Doctrines and Remedies, where they blamed "Lord Cooke's misguided endeavours" for what they saw as the Court of Appeal's unprincipled decisions concerning the merger of common law and equitable doctrines in New Zealand. The authors went on to remark "[t]hat one man could, in a few years, cause such destruction exposes the fragility of contemporary legal systems and the need for vigilant exposure and rooting out of error". However, not all their colleagues shared such concerns. Justice Kirby (of the High Court of Australia), in his 2008 W A Lee Lecture, noted that Lord Cooke's supposedly "heretical" views had in fact been accepted by many prominent jurists in the United Kingdom, including the House of Lords. He took issue with the tone of the Meagher Preface, remarking that "those familiar with the successive 'rooting out' of heretics in England under the later Tudors will recognise the genre of this denunciatory writing. Burning at the professional stake would seem too kind a fate for such doctrinal rascals."

Since 2002 the Law School of Victoria University, Wellington has held an annual lecture in his honour, predominately in the area of constitutional and administrative law.

Cooke was the only Commonwealth judge in the past century to sit in the Appellate Committee of the House of Lords on United Kingdom appeals. He adjudicated on nearly a hundred cases in the House of Lords and the Privy Council; his final case before retirement was Delaware v City of Westminster, in October 2001.

In 1996, Lord Cooke delivered the 47th Hamlyn Lecture Series, entitled Turning Points of the Common Law. In each of his four lectures, he focused on a single major case (covering public law, crime, tort and company law) and the influence of that case on the development of the common law as a whole throughout the Commonwealth.

Cooke himself had a formidable extrajudicial and academic presence. From 1992 until 1996, Cooke was General Editor of The Laws of New Zealand and selected the original authors for the different titles. He was also a prolific contributor to legal journals, including the Law Quarterly Review, Cambridge Law Journal and New Zealand Law Journal.

Perhaps the most famous public law case which Cooke decided came before him when he was President of the Court of Appeal. In Simpson v Attorney-General (commonly referred to as Baigent's case), the Court held that it is implicit in the New Zealand Bill of Rights Act 1990 that breaches of human rights by public officials could result in a claim for damages — even though there is no such provision in the Act itself. In the case, the Police had mistakenly carried out a search warrant at the wrong address. Because the occupant of the house was not charged with any crime, there was no obvious remedy for the Police's illegal search (exclusion of improperly obtained evidence being the usual remedy applied in Bill of Rights Act cases). In delivering the leading judgment, President Cooke remarked that "we [the Court] would fail in our duty if we did not give an effective remedy to a person whose legislatively affirmed rights have been infringed".

In 1987, Cooke delivered the judgment of the Court of Appeal in the landmark case of New Zealand Maori Council v Attorney-General, which sought to clarify what Parliament meant by section 9 of the State Owned Enterprises Act 1986. The Act stated "Nothing in this act shall permit the Crown to act in a manner that is inconsistent with the principles of the Treaty of Waitangi", but what those principles might be was left to the courts to decide. The principles elicited by President Cooke gave legal recognition to the special relationship between the Crown and Maori. Cooke held that "the Treaty created an enduring relationship of a fiduciary nature akin to a partnership, each party accepting a positive duty to act in good faith, fairly, reasonably and honourably towards the other". This principle of partnership continues to shape the legal relations between the Crown and Maori to this day.

He took a similar approach in 1985, when he delivered the judgment of the Court of Appeal in the case of Finnigan v New Zealand Rugby Football Union allowing the appeal of lawyers seeking an injunction against the NZRFU's proposed tour of South Africa. The proposed tour followed the controversial 1981 Springbok Tour, and was cancelled after the High Court re-heard the case in light of the Court of Appeal's judgment.

In Bulk Gas Users Group v Attorney-General, the then Justice Cooke delivered the leading judgment of the Court of Appeal. Cooke held that a privative clause in the Commerce Act 1975 did not prevent the courts from reviewing a decision made by the Secretary of Energy. He observed that "the Courts of general jurisdiction will be slow to conclude" that they are not permitted to rule on a question of law. This reluctance to accept the ouster of the court's jurisdiction was characteristic of Cooke's views on the importance of the courts' role in upholding the rule of law.

In 1972, he was appointed as a Judge of the (former) New Zealand Supreme Court (now High Court). He held this position until 1976 when he was elevated to the New Zealand Court of Appeal (at that time the country's highest local court). In 1986, he was appointed as President of that Court – a position he was to hold for the next 10 years. On his retirement from the Court of Appeal in 1996 Cook was granted a British life peerage as Baron Cooke of Thorndon, (a suburb of Wellington) in New Zealand and of Cambridge in the County of Cambridgeshire, becoming a member of the Appellate Committee of the House of Lords where he sat as a Lord of Appeal (Law Lord) until his retirement in 2001.

Cooke was a champion of the need to develop independent jurisprudence for New Zealand. In 1956, having recently returned from the United Kingdom, he criticised New Zealand's judiciary for its "unquestioning compliance" with English case law. By 1988, Lord Cooke was pleased to be able to report that "in virtually every major field of law New Zealand law is radically, or at least very considerably, different from English law". This change was thanks in part to his own efforts. Yet Lord Cooke did not believe that different jurisdictions had nothing to learn from each other. Rather, he believed that "[c]ommon denominators may be usefully sought, as long as the process is not compelled from outside and the national ethos is allowed its own weight."

The son of the Supreme Court judge, Justice Philip Brunskill Cooke QC MC and his wife, Valmai, Lord Cooke was born in Wellington and attended Wanganui Collegiate School. He graduated with an LL.M. from Victoria University College, and subsequently studied at Clare College, Cambridge as a Research Fellow. While on a travelling scholarship, Lord Cooke was awarded an MA in 1954 from Gonville and Caius College, Cambridge and subsequently a PhD in 1955.

In 1952, he married Annette Miller, with whom he had three sons. One of their sons, Francis, was appointed to the High Court in 2018.

Cooke was admitted to the New Zealand bar in 1950, and was also admitted to the English bar as a barrister of Inner Temple in 1954. He practised law in New Zealand as a barrister for almost twenty years, and was appointed as a Queen's Counsel in 1964. At age 38, that was the youngest appointment of a QC in New Zealand; the young age record had previously been held by his father, who had been appointed aged 43.

Robin Brunskill Cooke, Baron Cooke of Thorndon ONZ KBE PC QC (9 May 1926 – 30 August 2006) was a New Zealand judge and later a British Law Lord and member of the Judicial Committee of the Privy Council. He is widely considered one of New Zealand's most influential jurists, and is the only New Zealand judge to have sat in the House of Lords. He was a Non-Permanent Judge of the Court of Final Appeal of Hong Kong from 1997 to 2006.