Russell Cooke Bedford Row Holborn

About Katie

My role is to help people navigate what can be one of the most difficult times of their lives. I understand both the emotional and legal issues involved when a relationship breaks down and use my professional skills with my considerate but determined approach to get matters resolved in the best way possible.

Katie advises across the full breadth of family law with many of her cases involving an international element. She is a Resolution trained family mediator in financial and private law children matters.

Her specialist acumen is in cases involving international child relocation and disputes involving child arrangements. She advises on divorce, relationship breakdown and managing the associated financial matters. She also assists with the drafting of nuptial agreements. Her clients range from HNW individuals, international entrepreneurs and families of inherited wealth. 

Katie is ranked in Chambers HNW 2023 (Band 5 for Family/Matrimonial Finance: High Net Worth - London) as well as a Recommended Lawyer in Legal 500 2024.

Longmate is a really sensible, shrewd tactician."
Chambers HNW 2023


  • Read History at King’s College London, 2000-2003
  • Completed the General Diploma in Law (GDL) at the College of Law, London, 2003-2005


Katie qualified in 2007, joining the boutique family law firm Alexiou Fisher Philipps as a solicitor in 2011, later becoming a partner at the firm in 2016.

She has been involved in the following notable cases: 

  • Re L (Residence: Jurisdiction), the Court of Appeal case W (Children) on relocation
  • the influential High Court decision JKN v JCN addressing the jurisdiction of a transatlantic divorce


Katie is a:

  • member of Resolution and its Wellbeing Committee

Katie's highlights



Russell-Cooke grows family team with new partner Katie Longmate

Law firm Russell-Cooke has welcomed Katie Longmate as partner in the family team...
James Carroll, Joint Managing Partner in the Russell-Cooke Solicitors, family and children team. Family and children partner - Katie Longmate | Russell-Cooke
Multiple Authors
1 min Read
James Carroll, Katie Longmate
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