The Queen has spoken of her love for books that have a “life-enhancing power” after a series of allegations were made about the King in extracts from Earl Spencer’s memoir about the life of Diana, Princess of Wales.

Camilla was welcomed with applause to Chatsworth House in Derbyshire for the first day of the festival for The Queen’s Reading Room, a charity she founded following the success of her Instagram book club during the pandemic.

The charity is holding its fourth festival at the Grade I listed stately home in the Peak District on Saturday and Sunday.

The Queen was welcomed by Lord William Burlington, the chairman of The Chatsworth House Trust, who said it was “a huge thrill” to collaborate with The Queen’s Reading Room for a second consecutive year.

Camilla gave a speech in the Painted Hall and said being at Chatsworth House, which has a library of over 17,000 books, was “like coming home”.

She told the guests: “I created my Reading Room simply because, like all of us here, I love books and their life-enhancing power and I want to share that love with others.

“In those early days, I had no idea if anybody would be interested but six years on, we are a global community of millions from over 180 countries, swapping recommendations, undertaking research and donating thousands of books to women’s refuges and homeless shelters.”

She added: “There could hardly be a more fitting location for a literary festival than Chatsworth, a house that has inspired and hosted countless authors, including Charles Dickens, Elizabeth Gaskell and William Makepeace Thackeray, among many others.

“Future generations will, no doubt, boast of the day when William Boyd, Elif Shafak, Robert Harris and Kate Mosse were guests here too.”

Camilla’s speech about her love for reading comes after Earl Spencer made a series of damning claims about the King in a new memoir chronicling the life of his sister Diana that prompted an “unprecedented” response from Buckingham Palace who said, “the pain of fraternal grief can cloud reason”.

Earl Spencer further claimed that the King sounded “giddily elated… like a lottery winner” when he rang the earl following the princess’s death.

The book – Swan Song: Diana, My Sister – alleges that Charles subjected the earl to a “stream of anger” after he insisted Diana would not have wanted Princes William and Harry, then aged 15 and 12, to walk in her funeral procession.

In an extract of a BBC interview released on Friday, the earl insisted he is “telling the truth” and described the King’s comments about his sister as “monstrous”.

Wearing a blue dress, the Queen spoke to members of four local book clubs at Chatsworth House, including from the Elm Foundation, a charity which helps people affected by domestic abuse.

She then revealed her four book recommendations for autumn – Finding Belle by Reeta Chakrabarti, The Picture Of Dorian Gray by Oscar Wilde, Whistler by Ann Patchett and Sashenka by Simon Sebag Montefiore.

Journalist and news presenter Chakrabarti witnessed the unveiling of the chosen books and told the Queen: “Well, I don’t know what to say. Thank you so much for choosing it, and I’m going to read the others.”

Camilla said of Chakrabarti’s debut novel: “It’s a very good book, I highly recommend it to everybody.”

Writer and broadcaster Gyles Brandreth, who is one of the trustees of the charity, said: “Millions of people around the world are now reading books recommended by Her Majesty and people she’s invited to help her choose books.”

After the Queen gave her speech in the Painted Hall, she heard a performance of William Sieghart’s The Poetry Pharmacy, with readings by actress Natascha McElhone, known for her roles in The Truman Show, Ronin and Solaris.

In the Sculpture Gallery, The Queen attended a reception with literary figures taking part in the festival, including Lee Child, who wrote the Jack Reacher novel series and Turkish-British novelist Elif Shafak.