This weekend was Mothering Sunday (15 March) and, while the Royal Family almost certainly spent their time celebrating The Princess of Wales, Queen Camilla, Sophie, Duchess of Edinburgh and more, there was one other person who they also made sure was included. Taking to Instagram, Prince William shared a never-before-seen photograph of his late mother, Princess Diana, to pay tribute to her memory on the day. In fact, it appears he includes her in celebrations every year, and also teaches his children about the grandmother they never had the chance to meet.

Prince William shared a photograph of Princess Diana sitting in a meadow of flowers, playing with him when he was around toddler age. Prince William wrote a personal message as the caption saying, 'Remembering my mother, today and every day. Thinking of all those who are remembering someone they love today. Happy Mother’s Day. W'. Signing the note off with the letter 'W' tells us that the message came from Prince William personally, rather than it being written by a member of his team. Similarly, The Princess of Wales signs off her own with the letter 'C' for Catherine.

london, united kingdom october 22: princess diana helping prince william with a jigsaw puzzle toy in his playroom at home in kensington palace (photo by tim graham photo library via getty images)
Tim Graham
Princess Diana and a young Prince William in 1985.

As well as sharing memories of his mother publicly, Prince William also speaks to his children - Prince George, Princess Charlotte and Prince Louis - about their grandmother. The royal has even previously revealed handmade cards Princess Charlotte and Prince George made for Princess Diana.

Princess Charlotte's featured a multi-coloured heart surrounded by stickers of butterflies, flowers and a mouse dressed as a ballerina. In what appears to be her own hand-writing, she wrote a moving message, which also gave an insight into how her dad feels about his late mother.

london, england june 02: prince george, prince louis and princess charlotte in the carriage procession at trooping the colour during queen elizabeth ii platinum jubilee on june 02, 2022 in london, england. the platinum jubilee of elizabeth ii is being celebrated from june 2 to june 5, 2022, in the uk and commonwealth to mark the 70th anniversary of the accession of queen elizabeth ii on 6 february 1952. trooping the colour, also known as the queens birthday parade, is a military ceremony performed by regiments of the british army that has taken place since the mid 17th century. it marks the official birthday of the british sovereign. this year, from june 2 to june 5, 2022, there is the added celebration of the platinum jubilee of elizabeth ii in the uk and commonwealth to mark the 70th anniversary of her accession to the throne on 6 february 1952. (photo by karwai tang/wireimage)
Karwai Tang

'Dear Granny Diana,' she wrote. 'I am thinking of you on Mother's Day. I love you very much. Papa is missing you. Lots of Love, Charlotte xxxxxxxxx'. Her brother, Prince George wrote his own message saying, 'Dear granny Diana, Happy happy Mother's Day. I love you very much and think of you always, sending lots of love from George xxxxx.' At the time, Prince Louis was too young to write his own message but he still created a card with his name on for her. Swipe through the below post to see:

In a 2017 documentary, Prince William explained how he keeps her memory alive with his children. 'I regularly put George and Charlotte to bed, talk about her and just try to remind them that there are two grandmothers, there were two grandmothers in their lives. So it's important that they know who she was and that she existed,' he said, according to The Mirror.