The war widow stole Harry’s heart on a number visits Down Under, most recently when he and Meghan Markle greeted her among crowds of thousands during their royal tour last October.
But the popular prince has proved he’s not one to easily forget – penning his friend a touching letter just in time to celebrate her milestone.
“Dear Daphne, my wife and I send our warmest wishes to you on the occasion of your 99th birthday on Friday,” he wrote.
“We hope you have a wonderful celebration surrounded by family and friends and that you’ve managed to escape hospital.”
The tribute came after the pair garnered significant media attention across their three meetings, which have all happened during each of Harry’s official visits to Sydney since 2015.
But despite their obvious bond, Daphne wasn’t expecting anything from the father-to-be ahead of her big day – meaning the personal letter came as even more of a surprise.
“He wouldn’t even think of (sending well wishes),” she told the Today show last week.
As referenced in his message, Daphne had been in hospital for the past two months battling a severe bout of pneumonia.
Sadly, the great-grandmother succumb to the illness on Tuesday, less than a week after her birthday.