The King expressed his sadness when he met survivors of the Manchester synagogue attack during a visit to the congregation to deliver his sympathy in person.
Charles was introduced to the “heroes” by Rabbi Daniel Walker – a group of senior figures from the Heaton Park Hebrew Congregation Synagogue who helped stop Jihad Al-Shamie’s terror attack on the on the holiest day in the Jewish calendar.
“I can’t tell you how sad I am,” the King told the group, which included the synagogue’s chairman Alan Levy, who helped to barricade the door, and its president Hilary Foxler.
And later when he met other members of the congregation, the King commented “terrible thing to come out of the blue”.
When the attack began, Adrian Daulby, 53, leapt from his seat in the synagogue to block the doors of the Jewish holy place as knife-wielding Al-Shamie, 35, tried to get in to attack worshippers.
Melvin Cravitz, 66, was killed along with Mr Daulby, as the attack unfolded on Yom Kippur, the most holy day in the Jewish calendar, with many worshippers inside the synagogue in Crumpsall, north Manchester.
Mr Daulby is believed to have been inadvertently shot dead by armed police as they scrambled to the scene to stop Al-Shamie, who had driven his car at worshippers outside, attacked others with a knife and tried to storm the synagogue, wearing a fake suicide belt.
Yoni Finlay, 39, is also believed to have been injured by a police bullet and was discharged from hospital last week but looked well as he met the King with his parents.
He said afterwards: “Three weeks ago I saw the worst of humanity, but since then you do absolutely see the best, and there’s a lot of good people out there.”
Charles was making his first appearance at an official engagement since Prince Andrew’s decision to relinquish his titles left the King’s brother under intense public scrutiny.
Andrew attempted to draw a line after years of controversy, following allegations he sexually abused Virgina Guiffre, by giving up his dukedom and other honours on Friday ahead of the publication of Ms Guiffre’s posthumous memoirs.
The prince vehemently denied the allegations.
Later, Charles crossed the city to visit the headquarters of Greater Manchester Police (GMP), greeted on arrival by Sir Stephen Watson, the chief constable, and Andy Burnham, Mayor of Greater Manchester.
Charles held a private meeting with the police chief and some of the first responders on the day of the synagogue attack, before meeting more 999 workers who responded on the day.
The royal visitor spent around 30 minutes chatting to police, fire and ambulance crew who were on duty on the day, telling each group: “Thank you for your fantastic response.”
He also spent a moment talking to the police dog handler of Jimmy, a seven-year-old springador – a half-springer, half-Labrador police explosives sniffer dog.
Caroline Lloyd, the national interoperability officer (NILO) from North West Ambulance Service (NWAS), who attended the scene to help co-ordinate the emergency response, said: “It was a real pleasure to meet His Majesty today, it’s really kind of lifted our spirits up after a really difficult incident and hopefully lifted the spirits of the community he visited earlier.
Tom Weate, group manager for Greater Manchester Fire and Rescue Service (GMFRS), who took command of the fire response to the incident, said: ”I think the last few weeks has been a challenge for not only the community, but all agencies involved.
“It was a challenging day from all agencies’ point of view. It’s not something you expect to come to work for.”
Superintendent Kirsten Buggy, a police commander on the day, said: “It’s important to reflect as much as we are the people here who have had the privilege to meet the King, we are here representing all the first responders and the wider response from all our agencies.
“It’s been a challenging few weeks. He was keen to understand the role that we’d played, either on the day or subsequently.”
Mr Finlay, who helped barricade the synagogue door with others, said about returning to the place of worship: “It’s difficult because I know I’m lucky, we didn’t all make it and those are the real heroes.
“I didn’t do what anybody else wouldn’t have done but we’ve got a great community, everybody’s been really supportive.”
Asked about his conversation with the King, Mr Finlay replied: “He showed his support by being here, by asking us how we’re feeling, how we’re doing.”
During the visit the King met a relative of one to the two men killed and also security guard Bernard Agyemang, who was injured by the attacker’s car and appeared to be in a hospital gown and was pushed in a wheelchair.
Charles began his visit by spending a few minutes at an outside memorial area next to the synagogue where flowers and messages have been left by those paying their respects. He then had a private meeting with senior figures from the synagogue and Chief Rabbi Ephraim Mirvis.
The King later spent more than 20 minutes speaking privately with congregation members before going on an impromptu meet-and-greet with more than a hundred members of the Jewish community waiting outside who mobbed the head of state.
The synagogue’s chairman, Alan Levy, said: “For the King to come and show support to our community here and also the wider Jewish community, we’ve seen how many people were outside to see the King and cheering him, was just amazing.
“He was so nice and so humble. He said to me ‘If I can help in a small way, to help your community then it makes me happy’ and I said ‘you don’t realise Your Majesty how big it is for us and how much you’re helping us’.”
A Buckingham Palace spokesperson said about the visit: “This is the king continuing with duty and service in his longstanding mission to bring communities together particularly in times of challenge.
“And hopes very much that the focus will be on the community impacted rather than any other matters.”
Chief Rabbi Ephraim Mirvis, who accompanied the King on both visits in the city said: “Today has been a very special day. At the Heaton Park synagogue, His Majesty the King came, in order to express his condolences to the community following that awful terrorist attack on that awful day of Yom Kippur.
“He was with the injured, the bereaved families, the heroic members of the community and others and he brought so much encouragement. On behalf of the nation he was able to say to the community we care and we are together with you during this very challenging period.
“They are on an emotional rollercoaster ride because they have been through such a traumatic experience, now they have been cocooned by the love and affection and concern of so many people from around the country and indeed around the world and they do need encouragement and His Majesty was just amazing. Through his empathy, his understanding, his care and he certainly lifted those souls in a most magnificent way.”
Also on the visit to Manchester was Shabir Randeree CBE, chairman of the King’s Trust International charity and the British Muslim Trust, who engages in inter-faith dialogue work for Charles.
Mr Randeree said: “The fact that he made the time to come and meet people, victims and then their families at the synagogue actually speaks volumes for what he feels and the pain he himself takes on his shoulders from what happened on that horrible day.
“For me to see the inter-faith that he facilitates is hugely humbling. Without him a lot of interfaith would not happen. That’s a fact. He has an ability to bring people together.
“And Manchester I think was exemplary today in bringing people together of all different faiths.”
Afterward, the Mayor, Mr Burnham said: “I think it was tremendously important for the community, but also for everybody in Greater Manchester.
“I think the fact that the King is here, so soon afterwards means a great deal to everybody. I think it’s just a privilege to be in a room like this with truly the best of British, that’s what they are, aren’t they? Our emergency services.
“And to hear some of them reflect on what it means to them, the King has given them this time, I think it means a great deal and I think sometimes they are out there every day, doing what they do, when they get recognised like this, it is what it is all about.”