The Duke of Edinburgh will join the Queen when she visits a school to mark its centenary - his latest public engagement since announcing his retirement from public duties.
The Queen and Duke will celebrate the 100th anniversary of Pangbourne College in Berkshire, which has a long association with the monarch.
The visit will be the Queen's fifth to the fee-paying school since her first in 1943, as Princess Elizabeth.
On Thursday, Philip announced he will retire from public duties in the autumn, although his son the Earl of Wessex said he may still make appearances.
Edward said: "I don't believe he's going to be putting his feet up completely and disappearing into the background ... He'll pick and choose what he wants to do and how he wants to do it and what's practical.''
When the royal couple first arrive at the school they will attend a service in its Falkland Islands Memorial Chapel to mark the centenary of the institution.
It was founded in 1917 by shipowner and shipbroker Sir Thomas Lane Devitt as the Nautical College, Pangbourne near Reading.
His vision was to prepare boys to be officers in the Merchant Navy but by 1969, with the merchant fleet shrinking rapidly and many boys opting for university, the college shed much of the nautical training in favour of a more traditional academic focus and was renamed Pangbourne College.
After the service the Queen and Duke will meet current students, parents, staff and past pupils and also have lunch at the college.
Later, the royal couple will watch a parade and the Queen will present a new military flag, or colour, to the college, and two Queen's Gold Medals to the chief cadet captains.