Charles, 75, interrupted his traditional Scottish summer break at Balmoral to speak to those at the centre of the July 29 horror.
The monarch spent about 45 minutes in a private meeting with the survivors and their families before signing a book of condolence opened soon after the attack.
He used his own fountain pen to write his name and the date, then added: "In deepest sympathy." Today the King will host a meeting with the families of victims Bebe King, six, Elsie Dot Stancombe, seven, and Alice da Silva Aguiar, nine, in London.
The children were stabbed to death as they attended a Taylor Swift-themed dance workshop in the Merseyside town.
Ten others, including eight children, were seriously injured.
Arriving to loud cheers and applause from the appreciative waiting crowds, he viewed tributes of flowers and toys outside Southport's town hall before going inside to meet the survivors.
He expressed his "profound shock" over the tragedy and spoke of his heartfelt appreciation of the way the community rallied round in its aftermath as he met emergency crews, faith leaders and those who opened their doors in extraordinary acts of kindness.
They included Diane, 50, and her husband Dan, 48, whose home backs on to Hart Community Centre, where the horror unfolded.
Kind
Their shocked 12-year-old daughter witnessed the events from a window at home.
Charles heard how the couple comforted the families of some of the victims and continue to allow police to use their facilities.
Diane said afterwards: "It was a surreal conversation with the King, because we've opened our doors to the six or eight police officers who were manning the cordon each day.
"They get tea and coffee and food, but nowhere to go to the toilet. At night we leave our back door open for them to use the toilet too.
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
Howe defends spent promises
'RULE CHANGES HURT TOON'
Business as usual for Tigers despite missing Cheika
MICHAEL CHEIKA'S right-hand man at Leicester shrugged off the head coach's absence from today's clash at Newcastle after his touchline ban.
Ex-policewoman charged after paddleboard tragedy
A FORMER policewoman has been charged with gross negligence manslaughter following the deaths of four people in a paddleboarding incident.
Country star lashes out at 'hush money' rape claims
COUNTRY singer Garth Brooks has insisted that rape claims made against him by a stylist are a \"hush money\" shakedown.
Michel Roux: 'Potato Gate exit from BBC still hurts
MICHEL Roux Junior is still simmering at the BBC 10 years after he says he was forced out of MasterChef over a \"Potato Gate\" row.
Airstrikes threaten evacuations
IRAN'S CALL TO ARMS AS BRITISH AND U.S. HIT HOUTHI TARGETS
MONTELL: I'VE BEATEN THE BEST...BUT I'VE MET MY MATCH DANCING IN HEELS
SHE is formidable as Fire on TV's Gladiators, but Montell Douglas has finally met her match on Strictly-high heels.
PM's £22bn bid to capture carbon
SIR Keir Starmer rubbed shoulders with factory workers as he pledged nearly £22billion to capture and store carbon emissions from energy, industry and hydrogen production.
APOLOGY AFTER PROBE FINDS WOMEN SUBMARINERS SUFFERED MISOGYNY AND BULLYING
NAVAL personnel have been sacked after a probe uncovered \"intolerable\" misogyny and bullying on board nuclear-armed submarines.
Boris: Cameron wrong to quit after EU vote
BORIS Johnson has criticised David Cameron for quitting as PM after Britain voted to leave the European Union.
