Survivors of the Grenfell Tower fire have attended a memorial service at St Paul's Cathedral, alongside members of the Royal Family and PM Theresa May.
Bereaved families, survivors and rescue workers were joined by the Prince of Wales, the Duchess of Cornwall, the Duke and Duchess of Cambridge and Prince Harry.
Bishop of Kensington Graham Tomlin said he hoped the tragedy would represent a "time we learnt a new, better way".
The fire, on 14 June, claimed 71 lives.
The commemoration, marking six months since the tragedy, also gave thanks to all those who assisted at the time of the fire and since - including the emergency services, recovery teams, the community, public support workers and volunteers.
Archbishop of Canterbury Justin Welby, Labour leader Jeremy Corbyn and singer Adele were also among the more than 1,500 guests.
As the memorial began, a Green For Grenfell banner adorned with a heart was carried into the cathedral.
Opening the service ahead of a minute's silence, Dean of St Paul's Dr David Ison said: "We come together as different faiths as we remember those whose lives were lost."
"Be united in the face of suffering and sorrow," he added.
He said the UK grieved "at the unspeakable tragedy, loss and hurt of that June day".
Grief still raw
By Thomas Mackintosh, BBC News, at St Paul's Cathedral
Six months on from the Grenfell Tower fire, the grief and anger of those affected is still visibly raw.
Underneath the sadness there was dismay that many of the survivors attending the national memorial service at St Paul's Cathedral are still homeless.
And while those who died in the fire were remembered, there was also comment on what has taken place since - and what more importantly still needs to be done.
Families held photographs of victims of the fire, while voice recordings from people at the scene of the fire were played to the congregation.
'Hope' for change
The Al-Sadiq and Al-Zahra Schools Girls' Choir then sang out the words: "Never lose hope."
Graham Tomlin, Bishop of Kensington and organiser of the memorial, told the congregation: "Today we ask why warnings were not heeded, why a community was left feeling neglected, uncared for, not listened to."
But he said he looked ahead to the New Year with "hope" of change from "a city that didn't listen".
He said he hoped the word "Grenfell" would change from a symbol of "sorrow, grief or injustice" to "a symbol of the time we learnt a new and better way - to listen and to love".
Before the service, Bishop Tomlin told the BBC: "There was a very strong desire within the local community to have the service here, because faith is very important to a lot of people in the local area, and that can bring a real sense of strength to people."
One of those in attendance was Tiago Alves, who escaped the blaze with his family.
He told BBC Breakfast his thoughts would be with bereaved families during the "emotional" memorial: "Today is a day not about survivors; today is purely about the bereaved, their families and the loved ones they have lost."
He said the memorial would bring back a lot of awful memories for many people, but added: "The reason we are doing this today is so that people never forget - we want people to remember."
Portobello Road Salvation Army Band and St Paul's Cathedral Choir performed during the service, and the Ebony Steel Band, frequent performers at the Notting Hill Carnival, played a verse of Leonard Cohen's Hallelujah.
At the end of the service, bereaved families and survivors left the cathedral in silence, holding white roses.
Clarrie Mendy, who lost her cousin Mary and Mary's daughter, Khadija Saye, in the fire, said the memorial was "what the community needs, what the survivors need".
"It is a very emotional day," she said. "I just hope everybody will get something from it."
Councillor Elizabeth Campbell, leader of Royal Borough of Kensington and Chelsea, did not attend the service, after some families said they did not want the council there in an official capacity.
However, a minute's silence was held outside the town hall in High Street Kensington as the memorial service began.
The final death toll from the fire was put at 53 adults and 18 children, including stillborn baby Logan Gomes, following an arduous process of recovering and identifying remains from the block.
Earlier, Metropolitan Police Commissioner Cressida Dick said the force would do "whatever it takes" to bring to justice anyone who had committed a criminal offence linked to the fire.
Ms Dick said officers would investigate "meticulously, fairly and fearlessly", but said she would be "vey surprised" if the criminal investigation was completed within the next 12 months.
Scotland Yard has previously said it will be considering both individual and corporate manslaughter charges.