Charles Spencer became a grandfather this week, after his daughter, Lady Kitty Spencer, welcomed her first child with her husband, South African-British businessman Michael Lewis, who she married in 2021.
The 33-year-old shared the news on Instagram in a heartfelt post in honour of Mother's Day, writing: "It's the joy of my life to be your mummy, little one. I love you unconditionally. Happy Mother's Day to those who celebrate today."
Her father took to social media after his daughter's post, although he elected not to publicly comment on her huge news.
The Earl instead shared a very moving post where he paid tribute to the 'kindness and empathy' he experienced while recording the audio version of his upcoming memoir, A Very Private School.
Charles shared a series of images of himself behind the scenes at the recording studio, which he captioned: "Reading the audiobook for my new memoir, A Very Private School, was something I was slightly dreading.
"But I was very relieved at the end of the 3-day recording to realise that I wouldn’t have changed a single word of my book.
At the very end of the recording – and the final chapter is very raw indeed – the lovely lady producer who'd listened to me reading the book came over, and we just hugged one another, without a word. I will never forget her kindness and empathy."
The father-of-seven's book addresses his time at boarding school between the ages of eight and 13, as well as discussing the topic more generally, including stories from Charles' peers.
In the past, he has spoken frankly about how difficult this time in his life was, and said that he gave his children a choice when it came to their own education, writing about leaving home at such a young age: "I was dreading the enforced move from home.
"As a result, I've not expected any of my children to board, although two chose to "weekly board" (i.e., board in the week and come home every weekend), in their teens. Best to break the chain, and the pain."
The Earl shares eldest daughter Lady Kitty Spencer, twins Lady Amelia Spencer and Lady Eliza Spencer, 31, and his son and heir apparent Louis Spencer, Viscount Althorp, 19, with his first wife Victoria Lockwood.
With his second wife, Caroline Freud, he welcomed the Honourable Edmund Spencer in 2003 and Lady Lara Caroline Spencer in 2006. Charles and his third wife Karen Gordon share daughter Charlotte Diana, who is 11.
Kitty is the first of the author and podcaster's children to have a child, sharing the news only after giving birth following a pregnancy she kept under wraps.
The model's low-key pregnancy announcement was met with an outpouring of love from Lady Eliza and Lady Amelia, who rushed to the comments.
"The most perfect angel in the world," penned Amelia, while Eliza echoed with a gushing post: "My perfect little niece."
Lady Kitty got engaged to billionaire fashion mogul Michael, 63, in 2019. Two years later, the couple tied the knot in a lavish three-day wedding celebration at Villa Aldo Brandini in Rome with a glittering guest list.