House of Lords

===Former judicial role===
{{Main|Judicial functions of the House of Lords}}
Historically, the House of Lords held several judicial functions. Most notably, until 2009 the House of Lords served as the [[court of last resort]] for most instances of UK law. Since 1 October 2009 this role is now held by the [[Supreme Court of the United Kingdom]].

The Lords' judicial functions originated from the ancient role of the [[Curia Regis]] as a body that addressed the petitions of the King's subjects. The functions were exercised not by the whole House, but by a committee of "Law Lords". The bulk of the House's judicial business was conducted by the twelve [[Lords of Appeal in Ordinary]], who were specifically appointed for this purpose under the [[Appellate Jurisdiction Act 1876]].

The judicial functions could also be exercised by Lords of Appeal (other members of the House who happened to have held high judicial office). No Lord of Appeal in Ordinary or Lord of Appeal could sit judicially beyond the age of seventy-five. The judicial business of the Lords was supervised by the Senior Lord of Appeal in Ordinary and their deputy, the Second Senior Lord of Appeal in Ordinary.

The jurisdiction of the House of Lords extended, in civil and in criminal cases, to appeals from the courts of England and Wales, and of Northern Ireland. From Scotland, appeals were possible only in civil cases; Scotland's [[High Court of Justiciary]] is the highest court in criminal matters. The House of Lords was not the United Kingdom's only court of last resort; in some cases, the [[Judicial Committee of the Privy Council]] performs such a function. The jurisdiction of the Privy Council in the United Kingdom, however, is relatively restricted; it encompasses appeals from [[ecclesiastical]] courts, disputes under the [[House of Commons Disqualification Act 1975]], and a few other minor matters. Issues related to [[devolution]] were transferred from the Privy Council to the Supreme Court in 2009.

The twelve Law Lords did not all hear every case; rather, after World War II cases were heard by panels known as Appellate Committees, each of which normally consisted of five members (selected by the Senior Lord). An Appellate Committee hearing an important case could consist of more than five members. Though Appellate Committees met in separate committee rooms, judgement was given in the Lords Chamber itself. No further appeal lay from the House of Lords, although the House of Lords could refer a "preliminary question" to the [[European Court of Justice]] in cases involving an element of [[European Union law]], and a case could be brought at the [[European Court of Human Rights]] if the House of Lords did not provide a satisfactory remedy in cases where the [[European Convention on Human Rights]] was relevant.

A distinct judicial function—one in which the whole House used to participate—is that of [[Impeachment trial|trying impeachments]]. [[Impeachment in the United Kingdom|Impeachments]] were brought by the House of Commons, and tried in the House of Lords; a conviction required only a majority of the Lords voting. Impeachments, however, are to all intents and purposes obsolete; the last impeachment was that of [[Henry Dundas, 1st Viscount Melville]], in 1806.

Similarly, the House of Lords was once the court that tried peers charged with high [[treason]] or [[felony]]. The House would be presided over not by the Lord Chancellor, but by the [[Lord High Steward]], an official especially appointed for the occasion of the trial. If Parliament was not in session, then peers could be tried in a separate court, known as the Lord High Steward's Court. Only peers, their wives, and their widows (unless remarried) were entitled to [[List of trials of peers in the House of Lords|such trials]]; the Lords Spiritual were tried in ecclesiastical courts. In 1948, the right of peers to be tried in such special courts was abolished; now, they are tried in the regular courts.<ref>{{cite web|url=http://www.legislation.gov.uk/ukpga/Geo6/11-12/58/section/30/enacted/data.htm|title=Criminal Justice Act 1948|website=www.legislation.gov.uk}}</ref> The last such trial in the House was of [[Edward Russell, 26th Baron de Clifford]], in 1935. An illustrative dramatisation circa 1928 of a trial of a peer (the fictional [[Duke of Denver]]) on a charge of murder (a felony) is portrayed in the 1972 BBC Television adaption of [[Dorothy L. Sayers]]' [[Lord Peter Wimsey]] mystery ''[[Clouds of Witness]]''.

The [[Constitutional Reform Act 2005]] resulted in the creation of a separate Supreme Court of the United Kingdom, to which the judicial function of the House of Lords, and some of the judicial functions of the Judicial Committee of the Privy Council, were transferred. In addition, the office of Lord Chancellor was reformed by the act, removing his ability to act as both a government minister and a judge. This was motivated in part by concerns about the historical admixture of legislative, judicial, and executive power. The new Supreme Court is located at [[Middlesex Guildhall]].