The Queen gave birth to her first child, now King Charles III, on 14 November 1948 at Buckingham Palace, when she was 22 years old.
As her first born, eldest son and therefore heir to the throne, Her Majesty has always had a special bond with Charles.
Back in 2018, on the then Prince Charles' 70th Birthday the Queen delivered a powerful speech in celebration of her son's special day, which offered a hint at the strength of their relationship.
Her Majesty described her son as “passionate”, “creative” and as “a duchy original,” as she raised a toast to her heir in front of family, friends and members of European royalty at Buckingham Palace.
“It is a privilege for any mother to be able to propose a toast to her son on his 70th birthday,” she said. “It means that you have lived long enough to see your child grow up. It is rather like – to use an analogy I am certain will find favour – planting a tree and being able to watch it grow.
"Over his 70 years, Philip and I have seen Charles become a champion of conservation and the arts, a great charitable leader — a dedicated and respected heir to the throne to stand comparison with any in history — and a wonderful father," she continued. “Most of all, sustained by his wife Camilla, he is his own man, passionate and creative.
“So this toast is to wish a happy birthday to my son, in every respect a duchy original. To you Charles. To the Prince of Wales," she concluded.
“To my darling Mama, as you begin your last great journey to join my dear late Papa, I want simply to say this: thank you,” he said. “Thank you for your love and devotion to our family and to the family of nations you have served so diligently all these years.”
From enjoying cherished childhood moments together at home at Buckingham Palace, to sharing a joke at much-loved events and offering support at more sombre official engagements, the mother/son duo have shared some special memories over the years.
Here's a look back over some of their most heartwarming pictures together.