Princess Diana, who was tragically killed in a car crash in 1997, helped to launch Child Bereavement UK.
And now, 21 years later, her eldest son Prince William is its patron.
Speaking at a gala dinner to mark the 21st anniversary of Child Bereavement UK, the father-of-two paid a moving tribute to his late mother.
He said: "Twenty-one years ago last month, my mother attended the launch of the Child Bereavement Charity.
"Fifteen years later, I was honoured to be invited to become Patron of Child Bereavement UK to continue my mother's commitment to a charity which is very dear to me.
"What my mother recognised back then – and what I understand now – is that grief is the most painful experience that any child or parent can endure."
His Royal Highness added: “My mother was determined to help those in need and she would have been immensely proud – as I am – of all that Child Bereavement UK has achieved these last 21 years.
“When many people slink away at the sight of a friend's bereavement, CBUK's staff embrace strangers at the darkest moment in their life.
“I have witnessed first-hand the difference CBUK has made – and continues to make – to the lives of bereaved families.
“CBUK works with military families, with the wrecked families of suicide victims, with little children whose lives are torn apart by the inexplicable death of a parent.
“And yet amid all this misery, CBUK – and I don't know how they do this – brings warmth, comfort, a guiding hand, a way through, even colour and joyfulness, and a renewed opportunity for love as a family reknits itself after tragedy.”
Prince William finished emotionally: “As a father to two young children, I now appreciate it all the more.”
The Duke Of Cambridge, who was 15-years-old when he lost his mother, and Kate Middleton welcomed their second child, Princess Charlotte, in May 2015.
They are also proud parents to two year old Prince George.