Prince Harry will step in for the Queen and carry out a solemn engagement later on Tuesday. The royal will attend a service of commemoration at Westminster Abbey for the victims of the 2015 terrorist attacks in Tunisia.
The service will be held for family members of those who lost their lives, and for those who witnessed and were seriously injured in the attacks. It will be conducted by the Dean of Westminster.
Harry will lay a wreath at the Innocent Victims Memorial on behalf of Her Majesty before the service, and will deliver a reading during the service itself.
Prince Harry will attend a service to commemorate the British nationals who were sadly killed during the attacks
Last year two brutal attacks took place in Tunisia, the latter of which was the worst incident of terrorism involving British people since the 7/7 attacks in London 11 years ago.
On 26 June, a terrorist attacked tourists on the beach in the resort of Port El Kantaoui, and continued his attack into the Imperial Marhaba Hotel and on to the streets. He was later shot dead by Tunisian security forces, but not before killing 38 people, 30 of which were British nationals.
The tragic incident came just a few months after an attack on 18 March, when terrorists opened fire on tourists at the Bardo National Museum in Tunis. A total of 22 people, among them one British woman, was killed.
Harry will attend the service to commemorate the British nationals who were killed during the attacks.
Harry is stepping in for his grandmother The Queen
The 31-year-old royal has recently spoken about standing in for his grandmother the Queen and the huge responsibility that comes with it.
Speaking in a documentary Our Queen at Ninety, the Prince admitted: "People have always said, 'do you feel as though you are following in her footsteps?' That's exactly what we are doing. There is nowhere on this planet that I can think of, that she hasn't been in the last 90 years.
"She has been everywhere and that's sometimes quite hard, because you go to a place where she hasn't visited for maybe 20 years, maybe 15, and you just think to yourself, 'how can I ever fulfil this huge expectation that comes with her and being a member of her family?'"