To the outside world she was the woman who lived at the most famous address in London, but to the Queen Buckingham Palace was no more than the office, a place of work.
She began her life in more modest surroundings, relatively. Born not in a palace but a mansion, Number 17 Bruton Street in Mayfair, the home of her mother's parents, the Earl and Countess and Strathmore.
The Princess's first family home was 145 Piccadilly. When her father became King it was turned into a museum which the princess later visited with her sister, Princess Margaret.
Long before social media and even celebrity-chasing paparazzi, the young Princess was being groomed for a life in the spotlight.
But like tens of thousands of other young Londoners Princess Elizabeth's carefree childhood was about to be interrupted by war.
Buckingham Palace was bombed. The King and Queen stayed in town. Elizabeth and Margaret became evacuees, albeit to the luxury billet of Windsor Castle.
Despite the misgivings of her father Princess Elizabeth would be in uniform before the war was over, training at Camberley in Surrey as a driver and mechanic in the Auxillary Territorial Service.
"She actually really desperately wanted to partake in some military service but her father didn’t want her to.
"However she persisted and he eventually relented and she was able to join the auxiliary territorial service which was the women’s branch of the Army," said Dr Peter Johnson from the National Army Museum.
"She was working as a vehicle mechanic and driver so she was repairing vehicles, keeping them running, helping the delivery of supplies, keeping ambulances going. She was really living the full military life.
"The only difference for her that was instead of going back to barracks each day she went home to Windsor Castle," he added.
The great milestones in the Queen's life beginning with her Coronation and later her jubilees were an excuse for Londoners to join in the celebrations.
None more so than in 1977 when the Queen celebrated her Silver Jubilee and her subjects were invited to party.
All over London streets were decorated with flags and bunting, lines of tables were set up in the road.
At Barking, in east London, Joan Rawlinson and her daughter Claire were at a street party on the Scrattons Farm Estate.
Throughout her childhood Joan idolised the Queen and always wanted to meet her.
Her chance came during the Golden Jubilee in 2002 when Joan was a local councillor and was tasked with helping Barking's oldest resident present some flowers.
It didn't quite go to plan.
"Unfortunately when the Queen got to us, the dear old lady would not part with her flowers! I said I’m so sorry – she thinks they’re hers!" Joan said.
"And the Queen said to me ‘you can’t expect anything else at her age really can you!’
"All those years of wanting to meet The Queen, who I absolutely adored not only had I met her I’ve spoken with her.
"And the first thing I did was phone my mum.
"I said ‘mum guess what, I’ve spoken to The Queen’ and it took ages for it to sink in," she explained.
Decades of public engagements brought the Queen into regular contact with her fellow Londoners.
Many of her visits were to the charities she championed. London Zoo was a favourite.
The Queen's love of dogs led her inevitably into a long relationship with Britain's best known canine charity, Battersea Dogs and Cats Home.
"She was such a dog lover – particularly fond of corgis, she had them all her life. And I think what that meant was it made her really understand the issues," said Claire Horton from Battersea Dogs and Cats Home.
"She knew about animals, she certainly knew about an awful lot about dogs.
"When she came here she was able to talk to the people about the issues that they face and some of the challenges the animals come in with.
"It really made a difference to them and I really think to her too," she added.
The Queen always regarded Windsor as her home.
The fire at the castle in 1992 came at the end of a year which saw two of her sons separate from their wives, marking a low point in her reign.
When the Covid pandemic struck, the Queen chose Windsor as her safe haven during lockdown.
It meant she and Prince Philip were able to spend time together in the final year of his life.
The widowed monarch sitting alone in St George's chapel was a poignant image from the Duke's funeral.
Throughout her reign the Queen was an enduring and invaluable asset to London's tourist industry. The pageantry of celebrations and ceremonies a magnet for visitors from around the globe.
If they were lucky they got a glimpse of the monarch in a car or a coach or on a balcony.
Generations of priceless memories of the most famous Londoner in the world.
Despite her increasing frailty the Queen was determined there was one public duty she wanted to perform.
In May 2022 she made a last minute, surprise appearance at the opening ceremony of London's new railway named in her honour.
The Elizabeth Line.