Sentebale v Sussex: when charity disputes escalate to defamation claims

In August 2025, the Charity Commission concluded its investigation into Sentebale, the charity co-founded by the Duke of Sussex, and issued a Regulatory Action Plan after a well-publicised internal dispute that “severely impacted the charity’s reputation and risked undermining public trust in charities more generally”.

The situation has since taken a significant turn: Sentebale has issued High Court proceedings against the Duke of Sussex for defamation.

From regulatory action to litigation

The Commission’s inquiry painted a troubling picture of a charity divided by internal conflict. Rather than resolving disputes through proper governance channels, the parties’ disagreements spilled into the media, causing lasting reputational damage to the organisation.

The Regulatory Action Plan – a form of formal regulatory advice, rather than a direction or order – was intended to set Sentebale on a path to recovery.

However, on 24 March 2026, Sentebale filed a claim in the High Court against the Duke of Sussex and former trustee Mark Dyer, listed as “defamation – libel and slander”. The charity alleges the defendants orchestrated a “coordinated adverse media campaign” causing operational disruption and reputational harm. Both defendants deny the claims.

The litigation has been accompanied by further public accusations, including a previously undisclosed letter from former trustees. Written when they resigned in March 2025 and made public in April 2026, it alleges intimidation and misconduct by the current chair.

The decision by a charity to sue its own co-founder raises questions about the merits and prospects of the defamation claim, the governance obligations of trustees who authorise such litigation and the proper use of charitable resources.

Defamation: the statutory hurdle

It will be interesting to see how the claim plays out.

For a defamation claim to succeed, the claimant must satisfy a two stage test, as follows:

• The statement was defamatory in nature. It must have a “defamatory intent” on the part of the person making it. In essence, this means the statement caused or was likely to cause harm to the claimant’s reputation and that it was demonstrably false
• If they satisfy the first test, that they have suffered or are likely to suffer serious harm. Under the Defamation Act 2013, this is assessed financially. Therefore, a charity would need to show a significant drop in patronage (for example, gifts and donations) directly linked to the allegedly defamatory statements.

The test under the Defamation Act 2013 is deliberately stringent and arguably discourages weak or vexatious claims. The charity will therefore need to be confident in its prospects of success to pursue the litigation to trial.

The charity law dimension: governance under strain

The defamation claim will be determined on its own merits, but it doesn’t exist in a vacuum. The Commission’s earlier findings made clear that Sentebale’s governance had failed at a fundamental level.

Trustees are under a duty to act in the charity’s best interests, manage conflicts of interest and ensure disputes are handled in a way that doesn’t compromise its mission or standing. The Commission found those obligations had not been met.

The defamation proceedings raise an interesting interaction in charity law. Trustees who authorise litigation on behalf of a charity must be satisfied that doing so is in the charity’s best interests and represents a proper use of its resources.

This isn’t a decision to take lightly, particularly where the charity’s financial position is already precarious.

Financial pressures

Reporting on the charity’s accounts indicates that Sentebale’s financial position has come under significant strain. Free reserves were reportedly close to the charity’s minimum threshold by the end of 2024, alongside substantial staff reductions across its UK and African operations.

The charity itself maintains that it remains financially stable and operationally viable. Even on that more measured view, however, the allocation of resources to High Court litigation is likely to attract scrutiny.

Trustees have said legal costs are being met entirely by external funding, which may help address concerns about the use of charitable funds. However, external funders typically take a share of damages recovered if a claim succeeds.

The trustees – and the Commission – will need to be satisfied that any such arrangement is in the charity’s best interests, particularly if they have been advised that the claim has a strong prospect of success.

In any event, externally funded litigation still consumes trustee time and attention and carries a risk of further reputational harm. The Commission will be watching closely as the litigation progresses.

Lessons for the sector

The governance lessons identified in our previous article remain relevant, but recent developments reinforce them.

The pattern of escalation at Sentebale illustrates a risk for all charities: internal disputes, if not managed early, can take on a momentum of their own. Conflicts of interest policies, alternative dispute resolution clauses, clear terms of reference and well-drafted governing documents can help prevent this – and the cost of putting those mechanisms in place is negligible compared to the alternative.

The decision to litigate brings additional scrutiny. Where trustees authorise a claim, it should be supported by:

• Independent legal advice
• A clear assessment of prospects of success
• A realistic appraisal of costs and risks, including reputational exposure.

The Commission has shown it’s prepared to intervene where governance failures threaten public trust. Charities embroiled in public disputes should expect regulatory attention.

Sentebale was founded to support vulnerable young people in southern Africa. That mission has been overshadowed by a prolonged dispute that shows no sign of resolution.

The lesson for the sector is clear: charity disputes left unresolved don’t fade. They escalate, and it’s the charity’s beneficiaries who ultimately pay the price.