Charles Spencer shared his astonishment as he was reminded of a tribute concert he put on in memory of his late sister, Diana, Princess of Wales.
Musical duo Lighthouse Family shared their memories on Sunday, tweeting: "23 years ago today we played at the Diana, Princess of Wales Tribute Concert at Althorp House. A day we’ll never forget. Thank you for your amazing hospitality @cspencer1508."
In response, the Earl replied: "Goodness - I can’t believe this was 23 years ago…"
The Diana, Princess of Wales Tribute Concert took place on 27 June 1998, a few days before the date of what would have been her 37th birthday and almost a year after her tragic death.
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The event included some of Diana's favourite performers, including Cliff Richard, Chris de Burgh, David Hasselhoff, Duran Duran, Jimmy Ruffin, Lesley Garrett and Lawrence Gowan.
The concert took place at Diana's childhood, Althorp Park, and was attended by 15,000 people, with proceeds from ticket sales being donated to the Diana, Princess of Wales Memorial Fund.
Charles, 57, has been custodian of Althorp House in Northampton since the death of his father, John Spencer, in 1992.
The concert marked the first time that Althorp was opened to the public.
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The Princess of Wales Tribute Concert was attended by 15,000 people
Charles regularly shares updates about the Spencer family estate on his social media accounts, posting photos and videos of its beautiful grounds, priceless works of art and resident animals, including Tim the peacock.
Prince William and Prince Harry will be joined by Diana's close family at a statue unveiling of the late Princess at the Sunken Gardens at Kensington Palace on 1 July, on what would have marked Diana's 60th birthday.
The Duke of Sussex was pictured arriving in London from the US on Friday. Harry must self-isolate for five days until he is able to do a 'test to release', which will allow him to leave self-isolation once he receives a negative result.
He is staying at the Sussexes' UK residence, Frogmore Cottage, where his cousin, Princess Eugenie, now lives with her husband Jack Brooksbank and their baby son August, who was born in February.
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