The Duke and Duchess of Sussex are due to make their final public appearance as working members of the Royal Family.
Prince Harry and Meghan will join the Queen and other royals at the Commonwealth Day Service at Westminster Abbey on Monday afternoon.
The couple have been carrying out a series of public appearances in the UK before stepping back as working royals.
From 31 March, they will stop using their HRH titles and receiving public money.
The duke and duchess will gather with the Queen – who is head of the Commonwealth – the Prince of Wales, the Duchess of Cornwall and the Duke and Duchess of Cambridge in the central London cathedral.
It will be the first time the couple have appeared with other members of the Royal Family since announcing their intention to “step back” as senior royals in January.
After the service, they are expected to return to their current base in Canada, where their son, Archie, has remained during the UK trip.
It is where the couple are to begin their new life of personal independence, pursuing private commercial deals and charity projects.
Prince Harry and Meghan will retain use of Frogmore Cottage, in Windsor, and aides have said they will be in the UK regularly.
They will still attend some royal events but these will not be classed as official duties.
The new arrangements will be reviewed next year.
The duke and duchess have conducted a farewell tour of the UK with several appearances including the Endeavour Fund Awards and a military musical festival at the Royal Albert Hall.
