An hour-long ceremony in London Friday will mark the 10th anniversary of Princess Diana’s death.

The noon observance will be led by her sons Princes William and Harry at the Wellington Army barracks. Their stepmother Camilla was invited to attend but has declined.

The Prince of Wales’ official website announced the service arrangements earlier this week, stating that approximately 500 guests are expected to attend, along with more than 30 members of the Royal Family.

Diana’s oldest sister, Lady Sarah McCorquodale is also set to speak at the service.

The Paris car crash that claimed Princess Diana’s life also killed her boyfriend Dodi Fayed and their chauffeur.

The service is being broadcast live on the BBC and ITV.