“Lewis Marks KC is regarded as one of the outstanding family law advocates of his era, bringing exceptional strategic insight, persuasive advocacy and unrivalled expertise to the most complex financial and international family disputes. Trusted in landmark cases involving substantial wealth, intricate asset structures and cross-border challenges, he combines intellectual precision with practical judgement, earning a reputation as a leading authority in modern matrimonial finance litigation.”

Fantastic Lawyers® Editorial 2026

Lewis Marks KC is a leading family law barrister at Queen Elizabeth Building (QEB) in London. Called to the Bar in 1984 and appointed King’s Counsel in 2002, he has spent more than two decades at the forefront of high-value family law litigation.

Described by Chambers & Partners 2026 as “the most sophisticated family barrister at the Bar and the master of advocacy”, Lewis is recognised throughout the profession as a first-choice advocate for the most complex financial remedy and international family law disputes.

What Lewis Marks KC does

Lewis specialises in complex family law matters, particularly those involving substantial wealth, international assets and intricate financial structures.

His expertise includes:

• High net worth and ultra-high net worth divorce
• Complex financial remedy proceedings
• International family law disputes
• Cross-border divorce and jurisdiction disputes
• Business, trust and inherited wealth cases
• Financial provision claims for unmarried couples
• Schedule 1 Children Act claims
• Prenuptial and postnuptial agreement disputes
• Appeals and leading family law litigation
• Inheritance Act and family-related financial claims

Lewis is particularly known for handling cases involving entrepreneurs, business owners, international families, trusts, family offices and substantial corporate interests.

Why he stands out

Few family law advocates attract the level of praise consistently directed towards Lewis by fellow lawyers, judges and clients.

Chambers & Partners has described him as:

• “The most sophisticated family barrister at the Bar and the master of advocacy.”
• “In a league of his own when it comes to complex matrimonial finance work.”
• “The most persuasive advocate I’ve ever seen in our profession.”
• “A go-to adviser in complex money disputes involving ultra high net worth individuals.”

He is renowned for combining extraordinary technical ability with a calm, approachable manner. While many leading advocates are known for courtroom performance alone, Lewis is equally respected for identifying practical solutions and helping clients achieve settlements wherever possible.

His ability to analyse highly complex financial evidence, business structures and valuation issues has earned him a reputation as one of the most numerate and analytically gifted practitioners in family law.

Major cases and landmark litigation

Lewis has appeared in many of the most important financial remedy cases of the last three decades, including landmark decisions that have shaped modern family law.

His extensive case portfolio includes involvement in significant authorities such as:

• White v White
• Miller v Miller
• Dart v Dart
• Cooper-Hohn v Hohn
• Pierburg v Pierburg
• Bogolyubov v Bogolyubov
• Luckwell v Limata
• Versteegh v Versteegh
• Zimina v Zimin

His practice continues to involve some of the most challenging and high-value financial disputes before the Family Court, High Court and Court of Appeal.

Thought leadership and professional contributions

Lewis is not only a leading advocate but also one of the most influential contributors to family law practice and education.

He is:

• A Fellow of the International Academy of Matrimonial Lawyers (IAML)
• A long-standing member of the Family Law Bar Association
• A founder author of Financial Remedies Practice
• A long-time editorial board member of At A Glance, one of the profession’s most widely used financial remedies resources
• A contributor to AAG Cloud, a leading family law practice tool

These roles reflect the respect he commands across the family law profession and his ongoing influence on the development of matrimonial finance law.

Client approach

Despite his formidable reputation, Lewis is known for being approachable, accessible and empathetic. Clients frequently comment on his ability to explain highly complex legal and financial issues in clear, understandable language.

He prioritises efficient settlements wherever possible, recognising the emotional and financial cost of prolonged litigation. When court proceedings become necessary, however, he is recognised as one of the most effective advocates in the country.

Recognition and trust signals

• King’s Counsel since 2002
• Called to the Bar in 1984
• Consistently ranked in the highest tiers of Chambers & Partners and Legal 500
• Fellow of the International Academy of Matrimonial Lawyers
• Recognised authority on financial remedies and matrimonial finance
• Regularly instructed by many of the UK’s leading family law solicitors
• Appeared in numerous landmark family law cases