The sweet nod to Princess Diana in Charles' official 70th birthday photo montage

It was a touching tribute from the Prince of Wales to his beloved boys' mother.

Clarence House has included a photo of Princess Diana in a candid photo montage to celebrate Prince Charles' 70th birthday.
The shot featuring the late Princess of Wales with eight-month-old Prince Harry in her arms and her then-husband, Prince Charles carrying a two-year-old Prince William, was taken on the Royal Yacht Britannia when she was just 23.
It was one of a series of photos taken at a press call in 1985 at the end of the Royal Family's three-week tour of Italy that culminated in Venice, and was only four years after the couple made their wedding vows amid the splendour and pageantry of St Paul's Cathedral.
WATCH: Prince Charles' official 70th birthday photo montage in the player above. Story continues below...
Princess Diana cradling eight-month-old Prince Harry on the Royal Yacht Britannia in 1985. (Image: Getty)
The fact that it's 21 years after the much-loved Princess of Wales died in a horrific car crash in Paris and 26 years since the royal couple's separation was announced to the British public by then Prime Minister John Major means it's all the more touching – and indeed, fitting – that a photo of the self-proclaimed "People's Princess" should be part of Charles' birthday celebrations.
Seen with her trademark shy smile for the cameras and looking so very young and beautiful, Princess Diana's inclusion is a mark of respect for the woman who gave Prince Charles his two beloved sons and the British throne an heir in the shape of Prince William.
Commentators were divided on the montage. Some noted how happy the Prince looks with Camilla, Duchess of Cornwall who he married in 2005.

"How nice that he can marry Camilla and be truly happy because everyone in this life deserves to be happy," one said.
"While Diana was a good human she was not necessarily the best wife. Camilla is an amazing person in her own right and has stepped into the role fabulously, and makes Charles happy," another added.
Others, however, were not so impressed that there was only one photo of Princess Diana included.
"What a lack of maturity to put only [one] photo of Princess Diana," one commenter declared.
"You should have put more than one slide with Diana on it," another added.

But the majority were quick to come to the defence of the Prince, pointing out the entire point of the post - which was released on Clarence House's Twitter - was to celebrate Prince Charles' life.
"It's not about her. It's about Charles turning 70! Give it a rest," one wrote, while another highlighted there was also only one photo of the prince with his grandfather.
The gorgeous photos were released after a jam-packed week of back-to-back birthday gatherings, including an A-list concert held in his honour called We Are Most Amused and Amazed and a glittering private party with the Prince's nearest and dearest royal loved ones at Buckingham Palace.