Firm Profile

Three Crowns LLP

UK Guide 2025

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UK

Three Crowns LLP

Three Crowns LLP

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+44 20 3530 7950

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About

Provided by Three Crowns LLP
UK

Founded in 2014, Three Crowns is a specialist law firm dedicated to providing excellence in counselling and advocacy in international arbitration and international law. We have an established reputation of being the “go-to” firm for the resolution of complex and groundbreaking international disputes.

Members of our firm have acted on some of the largest and most significant international disputes in recent years. Our clients—leading corporates and sovereign States—entrust us with their largest and most important disputes. On their behalf, we have an outstanding track record of securing positive awards and settlements, including obtaining many of the precedent setting awards in the history of international arbitration and public international law.

With offices in key arbitration centres, our “one firm, one team” approach ensures that our clients receive a seamless service and dedicated lawyers on every mandate. Successful representation in international dispute resolution calls upon a unique blend of experience, creativity, forensic skill, and advocacy. Our way of working drives efficiency. We have found that lean teams closely managed by senior lawyers yield the best possible outcome substantively while preventing inefficiencies in work product and costs. We ensure that all our lawyers are incentivised properly by linking associate compensation to this qualitative input rather than quantity of hours billed. We also conduct our own advocacy and do not typically engage barristers for hearings.

Set out below is an introduction to our experience of international arbitrations arising in the commercial, investment treaty, and public international law fora. Our team has also a wide range of experience in arbitration- related domestic litigation.

COMMERCIAL ARBITRATION

Our experience in commercial arbitrations extends to representing corporate entities, private individuals, and States/State-owned entities. Clients approach us for our advice before a dispute has crystallised in order to assess their options prior to lodging a claim or where they anticipate a claim being brought against them. We have a deep-rooted understanding of the major commercial arbitral rules and have many decades of combined experience representing clients in the commonly used commercial arbitration seats.

INVESTMENT TREATY ARBITRATION

The firm’s investment treaty practice is a widely accepted market leader, with our lawyers having successfully represented clients in a number of historic cases. Unlike many other firms, we have significant experience acting both for and against States in investment treaty arbitration, and are therefore able to better anticipate and navigate the strategies and arguments that parties will typically pursue in such disputes.

We regularly advise our clients on investment protections relevant to them. This can be valuable to investors seeking to maximise protections available to their foreign investments, and to States seeking to reduce possible legal exposure arising from governmental measures.

PUBLIC INTERNATIONAL LAW

Our team has significant experience in inter-State disputes, including maritime delimitation and territorial disputes, the Law of the Sea, shared waterways, human rights, international trade, and international civil aviation.

We are familiar with working with government departments and external specialists from various disciplines to form straightforward and persuasive pleadings. Members of our team have appeared before the International Court of Justice, the International Tribunal for the Law of the Sea, United Nations bodies, domestic constitutional courts, World Trade Organization panels, and arbitral tribunals. Our public international law work also includes acting for clients on a pro bono basis.

ARBITRATION-RELATED LITIGATION

We have a wide range of experience acting before national courts, having represented clients before courts at all stages of the arbitral process, including in award enforcement.

Our team has appeared before the UK Supreme Court, including representing the ICC in the widely reported case of Halliburton v Chubb. We have also acted for clients in cases arising out of the 1996 Arbitration Act, including in proceedings where a party has sought to challenge an award on the basis of jurisdiction, irregularity or a point of law.

We have wide-ranging experience acting in pre- and post-arbitration litigation (enforcement and annulment proceedings) at all levels of the French court system. We regularly represent our clients before the French courts and our experience includes enforcing or resisting enforcement of awards against assets owned by sovereign States.

Our litigation experience extends to the U.S. Federal and State courts, for which we have undertaken numerous cases in relation to set aside proceedings, section 1782 applications, and amicus curiae briefs.

We also have experience developing strategies for and coordinating litigation proceedings across various jurisdictions in Asia, including in Singapore, China, India, Indonesia, Japan, Malaysia, Philippines, South Korea, Thailand, and Vietnam.

Ranked Offices

Provided by Three Crowns LLP

UK - Head office

Three Crowns LLP rankings

UK Guide 2025
Filter by
Band
UK-wide
Energy & Natural Resources: Disputes
2 Ranked Lawyers
Lawyers
Constantine Partasides KC
1
Constantine Partasides KC
1
Band 1
Gaëtan Verhoosel KC
3
Gaëtan Verhoosel KC
3
Band 3
International Arbitration
4 Ranked Lawyers
Lawyers
Constantine Partasides KC
Constantine Partasides KC
Star Individuals
Gaëtan Verhoosel KC
1
Gaëtan Verhoosel KC
1
Band 1
Reza Mohtashami KC
2
Reza Mohtashami KC
2
Band 2
Leilah Bruton
6
Leilah Bruton
6
Band 6
International Arbitration: Arbitrators
1 Ranked Lawyer
Lawyers
Constantine Partasides KC
1
Constantine Partasides KC
1
Band 1
International Arbitration: Commercial Arbitration
1 Department
Department
International Arbitration: Commercial Arbitration
1
International Arbitration: Commercial Arbitration
1
Band 1
International Arbitration: Investor-State Arbitration
1 Department
Department
International Arbitration: Investor-State Arbitration
1
International Arbitration: Investor-State Arbitration
1
Band 1
Public International Law
1 Department
2 Ranked Lawyers
Department
Public International Law
3
Public International Law
3
Band 3
Lawyers
Constantine Partasides KC
3
Constantine Partasides KC
3
Band 3
Gaëtan Verhoosel KC
3
Gaëtan Verhoosel KC
3
Band 3