She was
called to the bar at
Gray's Inn in 1971, and joined
Lincoln's Inn in 1973. She practised at Erskine Chambers from 1971 to 1993, mainly in
company law. She is an Honorary Fellow of Girton College, Cambridge,
Royal Holloway, University of London, and of
Liverpool John Moores University. becoming the first female High Court judge to be assigned to the
Chancery Division. As is customary, she was appointed a
Dame Commander of the Order of the British Empire (DBE) at the same time. Arden was chairman of the
Law Commission from 1996 to 1999. Other posts held by Arden include her membership of the Steering Group of the Company Law Review, and a current post as Head of International Judicial Relations for England and Wales. Arden's appointment to the
Supreme Court of the United Kingdom, replacing her husband Lord Mance on the court, was announced in June 2018, to take effect on 1 October 2018. On entering her office, she took the
judicial courtesy title of
Lady Arden of Heswall. She was the only woman out of the eleven judges of the court between the retirement of
Lady Black of Derwent in January 2021 and the appointment of Lady Black's successor,
Lady Rose of Colmworth, in April 2021. By the time she retired in 2022, she was the eldest of the justices (
Lord Lloyd-Jones was the second-eldest at 69). Following the retirement (and death) of
Lord Kerr of Tonaghmore in 2020 she was the only remaining member to have held judicial office before
31 March 1995 and was thus allowed to retire at 75 instead of 70. == Personal life ==