William Seagrim

William Seagrim

Year of Call: 2007

Clerks: James Watson / Lee Fifield

William specialises in family law, and he undertakes cases in all areas within that field. William is also the author of the practitioner’s text, Public Children Law: A Case Law Compendium (Bloomsbury, 2022).

William was in full-time practice at 9 Park Place Chambers from 2007 – 2015. He then practised part-time from 2015–2023, whilst lecturing at Cardiff University (lecturer then senior lecturer) and then Swansea University (senior lecturer). In October 2023, William resumes full-time tenancy at 9 Park Place Chambers. William is proud that during his time in academia he taught many students that are now junior barristers on the Wales and Chester Circuit, or further afield.

William has conducted serious and complex children law proceedings, including those concerning allegations of physical and/or sexual abuse, significant neglect, child-perpetrator/victims, parental alienation, domestic abuse, substance misuse and jurisdiction issues. William has dealt with financial remedies proceedings involving issues of MPS, inherited wealth, ‘conduct’ arguments, add-back, IVAs, family businesses, trust and thirds parties, and cohabitation disputes. William has appeared in notable cases, such as Re HA (a child) (no 2) [2015] EWHC 1310 (Fam), [2016] 1 FLR 966; Bristol City Council v AA & HA [2014] EWHC 1022 (Fam), [2015] 1 FLR 625; and LJ v JD [2013] EWHC 3632 (Fam), and he has been recommended in the Bar directory ‘Chambers and Partners UK’ (2015 - “He is deserving of wide recognition. He is an up-and-coming junior who is very confident and very able.” 2016 - “We were really impressed: he blew us away with the knowledge and familiarity with case law he displayed in his work.”)

William is published on family law issues. William authored the aforementioned book on child protection law (Public Children Law: A Case Law Compendium (Bloomsbury, 2022)); a book chapter on the significant harm test in children law (‘Best Interests: The “Gold Standard” or a Gold Plating? Should Significant Harm be a Threshold Criterion in Paediatric Cases?’, in K.A. Choong (ed) Medical Futility in Paediatrics: Interdisciplinary and International Perspectives (Trivent, 2019); and a journal article on experts in children cases (‘“No Questions, Your Honour” Challenging the unchallenged expert in closing: a permissible tactic in children cases?’ [2022] Fam Law 614 (co-authored with David Gareth Evans, of 9 Park Place Chambers). William has frequently provided CPD lectures and workshops to solicitors, barristers and social workers, and he was honoured to present a paper on a children law issue at the International Society of Family Law’s 18th World Conference, in Antwerp, Belgium (2023).


William obtained a 1st class LLB (Hons) degree (2005, Swansea University). William was the top final year law student at Swansea University and the joint recipient of the Sir Samuel Evans Prize (University of Wales, 2005), awarded for attaining the highest law grades across the then University of Wales group of universities (including Cardiff, Aberystwyth, Swansea, and Bangor Universities). William achieved an ‘Outstanding’ on the Bar Vocational Course (2007, Cardiff University) and was awarded the Lord Williams of Mostyn Achievement Award, as the outstanding student in witness handling (Cardiff University, 2007), and the Angel Chambers Prize, for achieving the highest results in Criminal Practice (Cardiff University, 2007). William is currently completing an MA in Education (University of Bath).

 Professional Membership

  • Wales and Chester Circuit
  • The Honourable Society of Gray’s Inn
  • Family Law Bar Association
  • International Society of Family Law