High Court rules 2014 will be invalid after finding late-onset schizophrenia undermined capacity
The High Court has overturned a will made in 2014 after concluding that the deceased lacked testamentary capacity due to serious mental illness, bringing an end to a long-running and complex family dispute and providing further clarification on the law governing capacity.
The case concerned the estate of Michael Gwilliam, from the Forest of Dean, who died in 2022. Proceedings were brought by his four daughters, who challenged the validity of a will executed eight years before his death. The court heard that the claimants were represented by Claire Cox, a partner at Gloucestershire law firm Willans LLP.
The High Court found that, at the time the 2014 will was made, Gwilliam was suffering from late-onset schizophrenia. His illness caused delusional beliefs that directly influenced the testamentary decisions he took. In particular, the court found that Gwilliam wrongly believed his daughters were stealing from him and had attempted to have him sectioned for financial gain. The court determined that these beliefs were unfounded.
Prior to making the disputed will, Gwilliam had expressed a wish to die intestate so that his four daughters would inherit his estate in full. However, on the advice of his sister, he later instructed an experienced paralegal to prepare a will. That will left the majority of his estate to his sister, an ex-girlfriend and his nephews, who were the defendants in the proceedings. Under its terms, his four daughters were collectively entitled to only 25 per cent of the estate.
In assessing the validity of the will, the High Court gave limited weight to the evidence of the will writer, who said she believed Gwilliam had capacity at the time of execution. The court ruled that the impact of his delusions meant he did not have the requisite testamentary capacity and that the will was therefore invalid. As a result, the court found that Gwilliam died intestate.
The judgment brings to a close a dispute that lasted more than four years and involved extensive medical records, witness evidence and expert psychiatric opinion. The written decision, published this week, runs to 99 pages.
Commenting on the outcome, Cox said the case demonstrated the importance of robust safeguards when preparing wills for individuals where capacity may be in doubt. She said the judgment reinforced good practice for solicitors, including the need to obtain contemporaneous capacity reports whenever concerns arise.
The case has wider significance for solicitors, families and professionals supporting older or vulnerable individuals, clarifying how mental illness and delusional beliefs can undermine testamentary decision-making.
Following the ruling, one of Gwilliam’s daughters said the legal team had provided clear guidance and steadfast support throughout the proceedings, adding that the outcome finally delivered justice for their father.