The Duke and Duchess of Edinburgh made a sombre appearance as they attended a memorial service at St Paul's Cathedral to mark the 20th anniversary of the 7/7 terror attacks.
Prince Edward and Sophie represented the King at the commemorations on Monday.
The royals joined survivors, bereaved families, members of the emergency services and senior politicians, including Prime Minister Keir Starmer and London Mayor Sadiq Khan.
On 7 July 2005, four bombs were detonated on transport systems in the capital, killing 52 people and injuring hundreds as three Tube trains and a bus were targeted.
Commemorations took place across London, with a minute's silence held to mark the time of the first explosion at 8:49 at Edgware Road station 20 years ago.
In a touching tribute, the King said, in part: "We should also remember the countless stories of extraordinary courage and compassion that emerged from the darkness of that day. The selfless bravery of our emergency services, transport workers, and fellow citizens who rushed towards danger to help strangers reminds us of the very best of humanity in the face of the very worst."
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© PA Images via Getty ImagesArrival
The Duke of Edinburgh exiting from his car upon arrival at the poignant service.
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© PA Images via Getty ImagesRespectful attire
Guests in attendance wore a black or a navy colour palette as a mark of respect.
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© PA Images via Getty ImagesHeading inside
Edward and Sophie were greeted at the steps of St Paul's Cathedral as they made their way inside the service.
The service featured hymns and readings from those in attendance.
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© Getty ImagesPrime Minister Keir Starmer
In a statement to mark the anniversary, the Prime Minister said: "Twenty years on from the 7/7 attacks, we remember all those whose lives were lost and those whose lives were changed forever.
"We honour the bravery of the first responders, and the strength of the survivors.
"Those who try to divide us will always fail."
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© Getty ImagesSadiq Khan
The London Mayor, who read a passage from the Bible at the service, said in a statement: "Today, we mark 20 years since the horrendous 7 July terror attacks shook our city.
"We remember the 52 people whose lives were cruelly stolen on that dark day and our thoughts and prayers remain with all of their loved ones, as well as the more than 700 people who were injured by these cowardly acts of hatred.
"We also pay tribute to those who ran towards danger on that terrible day. From emergency service personnel, to transport workers and members of the public who showed incredible courage and compassion by putting their own safety at risk to help those in need, their bravery and selflessness will never be forgotten.
"Two decades on - as we unite for a day of commemoration - I have a clear message for those who seek to spread division and sow hatred – you will never win.
"London's determination to stand together is stronger than ever. We will always choose hope over fear and unity over division as we continue building a safer London for everyone."
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© Getty ImagesTheresa May
Former Prime Minister Theresa May was among the senior politicians in attendance.
