Commercial Court refuses jurisdiction in $14 billion Russian dispute: Magomedov v TPG Group
On 17 January 2025, Mr Justice Bright handed down judgment in Magomedov…
Legal 500
“Mark is a brilliant junior. Keen, energetic with a first rate intellect and unmatched knowledge of law and procedure. He is a joy to work with and an invaluable member of any team.”
Mark Cullen specialises in commercial litigation, with a particular focus on civil fraud, offshore work and professional liability claims.
He has been instructed in some of the largest and most complex cases in the Business and Property Courts in recent years, including Magomedov & Ors v TPG Group Holdings & Ors, a “$13.8bn Russia dispute”, and Vneshprombank v Bedzhamov, involving strongly contested allegations of fraud and issues relating to the impact of sanctions.
His work spans multiple jurisdictions and his offshore practice reflects his expertise in civil fraud and asset tracing, shareholder disputes and claims against professionals.
Mark was admitted as an Attorney at Law in the Cayman Islands in 2018 and as a Barrister of the Eastern Caribbean Supreme Court (British Virgin Islands) in 2017, after having been called to the Bar in England and Wales in 2013.
Mark is ranked in the directories as a Leading Junior in his four main practice areas:
Mark has been described in the directories as someone who is “a powerful advocate who is always attuned to the judge’s thinking. He has sound judgement, is calm under pressure and inspires confidence.” “He is unflappable and always adds value” and is “a pleasure to work with. He is calm and considered, provides clear and practical advice, and is very responsive”. He “has an excellent work ethic and thinks deeply about the legal and commercial problems he is presented with. He has a very strong academic background, but refreshingly is focused on practical solutions. His knowledge of private international law is particularly useful for offshore work, and he also has a formidable command of areas of law that are always relevant to offshore disputes.”
Mark holds a M.A. in Law and a first class LL.M. from Jesus College, University of Cambridge, where he was awarded a Foundation Scholarship. His previous experience includes working as the Judicial Assistant to Lord Justice Maurice Kay, then the Vice-President of the Court of Appeal (Civil Division).
For further details of Mark’s ongoing and previous work, please see the individual practice areas below.
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“A first-rate junior with an analytical approach”– Legal 500 (2025)
“Mark is very calm under pressure and a real team player. He is unflappable and always adds value” – Legal 500 (2024)
Mark is recognised as a leading junior for civil fraud work and has been involved in some of the largest and most complex cases in this area in recent years. Reflecting his broader practice, Mark is particularly sought after for cases with an international or offshore dimension.
Featured Civil Fraud cases
“Mark is an outstanding junior. He is exceptionally bright, has a brilliant legal mind and is incredibly hard working”- Legal 500, The English Bar Offshore (2025)
“Mark is a brilliant junior. Keen, energetic with a first rate intellect and unmatched knowledge of law and procedure. He is a joy to work with and an invaluable member of any team” – Legal 500, The English Bar Offshore (2024)
“Mark has an excellent work ethic and thinks deeply about the legal and commercial problems he is presented with. He has a very strong academic background, but refreshingly is focused on practical solutions. His knowledge of private international law is particularly useful for offshore work, and he also has a formidable command of areas of law that are always relevant to offshore disputes” – Legal 500 Caribbean, The English Bar Offshore (2023)
He was previously recognised by the Legal 500 as a “Rising star” for offshore work and described as “An impressive junior with experience beyond his seniority in offshore work.”
Mark has a significant offshore practice and was admitted as an Attorney at Law in the Cayman Islands in 2018 and as a Barrister of the Eastern Caribbean Supreme Court (British Virgin Islands) in 2017.
Mark has appeared as sole and junior counsel in the BVI Commercial Court and as junior counsel in the Financial Services Division of the Grand Court of the Cayman Islands. He also has significant experience of litigating in Antigua and Barbuda and the Isle of Man.
Reflecting his broader practice, he has particular expertise of claims involving allegations of civil fraud and offshore claims against professionals. He also has experience of shareholder disputes and contentious insolvency matters.
Featured Offshore cases
“Mark is a pleasure to work with. He is calm and considered, provides clear and practical advice, and is very responsive.” Legal 500 (2025)
Mark has acted in a wide range of commercial and business disputes, including shareholder disputes. Mark’s work frequently has an international or offshore element to it and he has experience of jurisdictional challenges and forum disputes.
He also has experience of insurance disputes in a commercial context and was part of the COMBAR Working Group looking at the impact of Brexit on commercial insurance (with Leigh-Ann Mulcahy KC and Ben Lynch KC).
Featured Commercial Litigation cases
“Mark is prompt, responsive and hard-working. His advice is comprehensive and pragmatic. He is a pleasure to work with” – Legal 500
“His advice is comprehensive and clear, which demonstrates significant attention to detail and a deep rooted understanding of the complex issues” – Legal 500
“A powerful advocate who is always attuned to the judge’s thinking. He has sound judgement, is calm under pressure and inspires confidence” – Legal 500
Mark has significant experience of acting for and against professionals in a range of high value, complex and sensitive cases, with particular expertise in relation to claims against lawyers, directors and fund managers and claims involving allegations of civil fraud or involving an offshore or international element.
Featured Professional Negligence cases
Mark is developing his practice in sports law, with a particular focus on football-related matters and commercial disputes in a sports context.
Featured Sports Law cases
Mark is developing his practice in international arbitration. He has experience of commercial and construction disputes.
Featured International Arbitrations
Education:
M.A. (Cantab) LL.M. (Cantab)
Bar Admissions:
England and Wales: 2013
British Virgin Islands: 2017
Cayman Islands: 2018
Memberships:
Commercial Bar Association
Chancery Bar Association
Professional Negligence Bar Association
Commercial Fraud Lawyers Association
On 17 January 2025, Mr Justice Bright handed down judgment in Magomedov…
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