The Duke of Edinburgh will meet Royal Marines in his final public engagement before he retires from royal duties.
The 96-year-old announced his retirement in May, after decades of supporting the Queen, as well as attending events for his own charities and organisations.
Prince Philip has completed 22,219 solo engagements since 1952.
On Wednesday, he will meet servicemen who have taken part in a 1,664-mile trek in aid of charity.
As Captain General of the Royal Marines, the duke will attend a parade to mark the finale of the 1664 Global Challenge – a series of strength and endurance challenges raising funds and awareness for charity.
The Queen’s public schedule will continue as normal.
Lady Myra Butter has known Prince Philip since the age of eight or nine and told Radio 4’s Today he was “very spirited, a young normal boy full of fun… we loved when he came to stay”.
Asked about what the duke would do next, she said: “I’m sure that he won’t disappear, he will be greatly missed by everybody.
“He’s been such a stable character in all our lives – he’s always there and he’s always been there for the Queen and I think we’re very, very lucky to have him.”
The Duke of Edinburgh 96 years old
70 years as Queen’s companion
22,219 solo engagements since 1952
5,496 speeches given
785 organisations have him as patron, president or member
4 million people have taken part in Duke of Edinburgh Awards
Source: Buckingham Palace