Background: The 11 Supreme Court judges ruling on prorogation case

- Lady Hale, 74, was appointed the first female president of the Supreme Court in 2017 after a varied career as an academic lawyer, law reformer and judge.

A long-standing champion of diversity in the judiciary, she became the first female justice of the court in October 2009, and was appointed deputy president in June 2013.

READ MORE: Here's what you need to know about tomorrow's Supreme Court ruling

During her time as deputy president, Yorkshire-born Lady Hale ruled on numerous high-profile cases, including the Brexit appeal.

- Lord Reed, 63, was appointed deputy president of the Supreme Court in June last year and will replace Lady Hale when she retires in January.

One of the court's two Scottish justices, he previously served as a judge in Scotland and sometimes sits as a judge at the European Court of Human Rights and the Hong Kong Court of Final Appeal.

He was educated at the universities of Edinburgh and Oxford before qualifying as an advocate in Scotland and a barrister in England and Wales.

- Lord Kerr, 71, is the first justice of the court to come from Northern Ireland, where he served as Lord Chief Justice from 2004 to 2009.

Educated at St Colman's College, Newry, and Queen's University, Belfast, he was called to the Bar of Northern Ireland in 1970, and to the Bar of England and Wales in 1974.

Top row, from left: Lord Sales, Lady Arden, Lady Black, Lord Kerr; second row, from left: Lord Hodge, Lady Hale, Lord Kitchin, Lord Lloyd-Jones; bottom row, from left: Lord Carnwath, Lord Wilson, Lord Reed

- Lord Wilson, 74, was appointed in 2009, having previously been a judge in the High Court's family division and the Court of Appeal.

- Lord Carnwath, 74, studied at Cambridge and was called to the Bar in 1968. He served as attorney general to the Prince of Wales from 1988 to 1994.

While a judge of the Chancery Division, he was also chairman of the Law Commission and, between 2007 and 2012, was Senior President of Tribunals.

- Lord Hodge, 66, the court's other Scottish justice, was previously the Scottish judge in Exchequer Causes, one of the Scottish intellectual property judges, a judge in the Lands Valuation Appeal Court and a commercial judge.

- Lady Black, 65, a justice since 2017, carried out a broad range of civil and criminal work during her early career as a barrister before specialising in family law.

She has served as a High Court judge and Lady Justice of Appeal.

Lady Black taught law at Leeds Polytechnic in the 1980s, was a founding author of the definitive guide to family law practice in England and Wales, and continues to serve as a consulting editor.

- Lord Lloyd-Jones, 67, was born and brought up in Pontypridd, South Wales, where his father was a school teacher, and is the court's first justice to come from Wales.

A Welsh speaker, he was appointed to the High Court in 2005, and acted as adviser to the court in the Pinochet litigation before the House of Lords.

- Lady Arden, 72, who grew up in Liverpool, began her judicial career in 1993 after working as a barrister, QC, and attorney general of the Duchy of Lancaster.

She became a member of the Permanent Court of Arbitration in The Hague in 2011, and sits as a judge of the European Court of Human Rights in Strasbourg.

- Lord Kitchin, 64, was called to the Bar in 1977 and his practice covered intellectual property, including patents, trademarks, copyright, designs and trade secrets.

He has also served as a High Court judge and as a Lord Justice of Appeal.

- Lord Sales, 57, is the youngest of the court's justices and was appointed in January, having worked as a barrister and QC before his appointment to the High Court in 2008.

He was vice-president of the Investigatory Powers Tribunal, served as deputy chairman of the Boundary Commission for England and was appointed as a Lord Justice of Appeal.

- The judges try to reach a unanimous decision on any case if possible, but there may be a majority ruling in favour of a particular outcome.

- They may also reach different conclusions on different legal aspects of the case and there is no minimum majority required.

- Lady Hale, Lord Reed, Lord Wilson, Lord Hodge, Lord Lloyd-Jones, Lady Arden and Lord Kitchin will attend the announcement of the court's decision on Tuesday.

HISTORY

The Supreme Court replaced the Appellate Committee of the House of Lords as the highest court in the UK in 2009.

The change resulted in the court's 12 justices becoming explicitly separate from both Government and Parliament.

The court hears appeals on cases of the greatest public importance, where it is considered there is an arguable point of law.

In civil law it hears cases from the whole of the UK and it considers appeals in criminal cases from England, Wales and Northern Ireland.

The court also considers devolution matters, which were previously heard by the Judicial Committee of the Privy Council.

The Supreme Court sits in the former Middlesex Guildhall, on the western side of Parliament Square.

A synopsis on the court's website says: "This new location is highly symbolic of the United Kingdom's separation of powers, balancing judiciary and legislature across the open space of Parliament Square, with the other two sides occupied by the executive (the Treasury building) and the church (Westminster Abbey)."

The court also sat in Belfast for the first time in May last year and in Cardiff in July this year.

The Miller and Cherry cases were heard by a panel of 11 justices, made up of the court's president Lady Hale, deputy president Lord Reed, Lord Kerr, Lord Wilson, Lord Carnwath, Lord Hodge, Lady Black, Lord Lloyd-Jones, Lady Arden, Lord Kitchin and Lord Sales.

It is only the second case to be heard by an 11-strong panel, the first being Miller's challenge over the triggering of the Article 50 process to start the Brexit countdown.