Lords of Appeal in Ordinary, commonly known as Law Lords, were appointed under the Appellate Jurisdiction Act 1876 to the House of Lords of the United Kingdom in order to exercise its judicial functions, which included acting as the highest court of appeal for most domestic matters. The House of Lords, however, lost its judicial functions upon the establishment of the Supreme Court of the United Kingdom in October 2009; those in office became Justices of the Supreme Court of the United Kingdom, and those Supreme Court justices that have seats in the House of Lords lost their right to speak and vote there until their retirement as justices of the new court.
To be appointed a Lord of Appeal in Ordinary under the 1876 Act, an individual was required to have been a practising barrister for a period of fifteen years or to have held a high judicial office — Lord Chancellor (before 2005) or judge of the Court of Appeal, High Court or Court of Session—for a period of two years. Lords of Appeal in Ordinary were required to retire from judicial office at 70 or 75 years of age, though as peers under the style of Baron they continued to serve as members of the House of Lords in its legislative capacity for life.
Lords of Appeal in Ordinary were occasionally joined by other Lords of Appeal in exercising the judicial functions of the House of Lords. Lords of Appeal included holders or former holders of high judicial office who were members of the House of Lords, but not by virtue of the Appellate Jurisdiction Act (e.g. life peers under the Life Peerages Act 1958). The Lords of Appeal continue to hold the style for life.
The House of Lords historically had jurisdiction to hear appeals from the lower courts. Theoretically, the appeals were to the King- or Queen-in-Parliament, but the House of Commons does not participate in judicial matters. The House of Lords did not necessarily include judges, but it was formerly attended by several judges who gave their opinions when the Lords desired. They did not, however, have the power to vote in the House. In 1856, to permit legally qualified members to exercise the House's appellate functions without allowing their heirs to swell the size of the House, Sir James Parke, a judge, was created a life peer. The House of Lords refused to admit him, so he had to take his seat as a hereditary peer.
In 1873, William Ewart Gladstone's government passed the Judicature Act, which reorganised the court system and abolished the appellate jurisdiction of the House of Lords in respect of English appeals. In February of the next year, before the Act came into force, Gladstone's Liberal Government fell; the Conservative Benjamin Disraeli became Prime Minister. In 1874 and 1875, acts were passed delaying the coming-into-force of the Judicature Act 1873. The Appellate Jurisdiction Act 1876 repealed the provisions rescinding the jurisdiction of the House of Lords. Additionally, the Act provided for the appointment of two persons to be Lords of Appeal in Ordinary, who were to sit in the House of Lords under the dignity of baron. Originally, though they held the rank of baron for life, they served in Parliament only while holding judicial office; 11 years later, however, an act was passed allowing Lords of Appeal to continue to sit and vote in Parliament even after retirement from office.
The statutory retirement age for Lords of Appeal in Ordinary depended on when they were first appointed to judicial office: for those who first became a judge before 31 March 1995, the retirement age is 75 years of age; for those appointed on or after that date, retirement was at 70 years of age (though they were permitted to continue sitting in a part-time capacity as a "Lord of Appeal" until the age of 75 years). There have been recent suggestions that the retirement age for the United Kingdom's most senior judges should revert to 75 years of age.
The Lords of Appeal in Ordinary were joined by the Lords of Appeal, who include members of the House of Lords, not necessarily created under the Appellate Jurisdiction Act, who held or had held high judicial office. Lords of Appeal retained their titles for life but were incapable of hearing cases after the age of 75. Only Lords of Appeal in Ordinary received salaries: in 2004, the salary for the Senior Lord of Appeal in Ordinary was £185,705, and for other Lords of Appeal in Ordinary it was £179,431.
The Appellate Jurisdiction Act 1876 originally provided for the appointment of two Lords of Appeal in Ordinary, who would continue to serve while holding judicial office, though in 1887, they were permitted to continue to sit in the House of Lords for life, under the style and dignity of Baron. The number of Lords of Appeal in Ordinary was increased from time to time—to three in 1882, to four in 1891, to six in 1913, to seven in 1919, to nine in 1947, to eleven in 1968 and to twelve in 1994. The Administration of Justice Act 1968 allowed the Sovereign to make a Statutory Instrument, if each House of Parliament passed a resolution approving a draft of the same, increasing the maximum number of Lords of Appeal in Ordinary.
The two most senior Lords of Appeal in Ordinary were designated the Senior and Second Senior Lords of Appeal in Ordinary respectively. The Senior Lord of Appeal in Ordinary historically was the Law Lord who was senior by virtue of having served in the House for the longest period. With the appointment of Lord Bingham of Cornhill in 2000, however, it became an appointed position.
The Second Senior Lord of Appeal in Ordinary became the peer who had served for the longest period. Lord Hope of Craighead succeeded to this position on Lord Hoffmann's retirement on 20 April 2009.