It was unveiled by Diana’s former flatmate, Virginia Clarke. It marks Coleherne Court on the Old Brompton Road, where the royal lived at Flat 60.
Diana stayed at the apartment at the time of her engagement to the Prince Charles in 1981.
She described her time at Coleherne Court as one of the happiest of her life.
Princess Diana news: A blue plaque has been unveiled at Diana’s old flat
Princess Diana news: An English Heritage London plaque is now on Coleherne Court
Ms Clarke said she and Diana shared “happy days” with the future Princess of Wales.
She said at the unveiling: “Those were happy days for all of us and the flat was always full of laughter.
“Diana went off to become so much to so many.
“It’s wonderful that her legacy will be remembered in this way.”
Princess Diana news: Virginia Clarke said she and Diana shared ‘happy days’ at the flat
Princess Diana news: Diana lived at the flat before dating Prince Charles in 1981
Ms Eavis said: “Diana was one of the world’s most famous women and she used her fame and influence to raise awareness of issues such as homelessness and landmines.
“She played a critically important role in helping to destigmatise illnesses such as HIV, leprosy and depression.
“It is fitting that our blue plaque remembers her at this place where her life in the public eye first began.”
Mr Boff added: “Diana had, and still has, a very special place in the hearts of Londoners and we are thrilled to see her blue plaque formally placed as a monument to her work for others.”
Princess Diana news: Prince Harry and Prince William unveiled a statue of the royal in July
The royal brothers commissioned the tribute, located in Kensington Palace’s Sunken Garden, in 2017 to help visitors “reflect on her life and her legacy”.
Harry and William added in a joint statement they hope the statue will “be seen forever as a symbol of [Diana’s] life and her legacy”.
They said at the time: “Today, on what would have been our mother’s 60th birthday, we remember her love, strength and character – qualities that made her a force for good around the world, changing countless lives for the better.”
Sarah Ferguson praised the statue of Diana and said the two brothers brought “unity and togetherness” in the royal family.
She told Australian Women’s Weekly: “The statue brought unity and togetherness to the family and I’m glad that my loyal friend has been honoured in this way.”
Omid Scobie and Carolyn Durand wrote in their book ‘Finding Freedom’ of how Harry’s friend said “both brothers are deeply devoted to carrying on their mother’s legacy and no amount of hurt feelings would ever get in the way of that”.
The friend added: “It is an absolute priority and even amidst this other stuff, they simply wouldn’t proceed without one another together.”
Source: EXPRESS CO UK