|Prince Philip announced his retirement from royal duties in May|
The Duke of Edinburgh's final official royal engagement before retirement has been announced.
Prince Philip will attend a parade at Buckingham Palace on 2 August to mark the finale of the Royal Marines 1664 Global Challenge, a palace spokeswoman said.
Buckingham Palace announced in May that the Duke would give up his official public duties from the autumn.
A palace spokeswoman said the parade in August would "bring His Royal Highness's individual programme to a conclusion, although he may choose to attend certain events, alongside the Queen, from time to time".
Prince Philip became Captain General of the Royal Marines in 1953, replacing King George VI after his death.
The Duke, who turned 96 last month, will attend the parade which raises money for The Royal Marines Charity.
This year marines from around the country have run 16.64 miles each day for 100 days, totalling a distance of 1,664 miles.