Prince Harry joined the loved ones of Britons killed in terror attacks in Tunisia at a special memorial service at Westminster Abbey.
Harry laid a wreath at the Innocent Victims Memorial on behalf of his grandmother the Queen as he gathered with survivors and families affected by the two atrocities in 2015.
He also delivered a reading during the central London service, which was conducted by the Dean of Westminster, the Very Reverend Dr John Hall, and attended by David Cameron.
Members of public looked on outside the Abbey as Harry, wearing a dark blue suit, laid the wreath of white and yellow flowers before rising and bowing his head in a moment of silent reflection.
The circular stone and slate memorial was unveiled by the Queen in 1998 and created to remember victims of war, violence and oppression across the world.
During the service, Harry and the Prime Minister both read Bible passages, from Revelations and Isaiah respectively, before the 900-strong congregation.
The Very Reverend Dr Hall said: "We remember with thanksgiving those whose lives were brutally cut short.
"We honour the courage of those who survived and the families of those who suffered.
"We share our grief with victims of attacks from other countries and their families."
Thirty Britons were among 38 people massacred in the Tunisian resort town of Sousse in June last year - the worst incident of terrorism involving British people since the July 7 attacks in London in 2005.
Gunman Seifeddine Rezgui targeted holidaymakers on the beach and in a hotel before being shot dead by security forces. Terror group Islamic State (IS) claimed responsibility.
Among those killed was engineer Stephen Mellor, from Bodmin, Cornwall, who died as he shielded his wife Cheryl.
Three generations of one family also died when Joel Richards, 19, a University of Worcester student and talented football referee, and his uncle Adrian Evans, 49, and grandfather Charles "Patrick" Evans, 78, were gunned down. Joel's teenage brother Owen survived the attack.
Three months earlier, IS terrorists opened fire on tourists at the Bardo National Museum in the capital Tunis. British tourist Sally Adey, 57, from Shropshire, was among 22 people killed.