The late Princess Diana has remained an important role in her son's lives, including helping them find the loves of their lives.
"I put it to William, particularly, that if you find someone you love in life, you must hang onto it and look after it," Diana told BBC at the time. "And if you were lucky enough to find someone who loves you, then one must protect it."
Although Diana offered this advice at a time when her marriage to their father, Prince Charles, was on the rocks, the message is still clear: if you love someone, don't let them go.
The boys — then 13 and 11 years old — certainly took this to heart, as both have done just that. Prince William fell in love with his college sweetheart Kate Middleton in 2004, later noting, "When I first met Kate I knew there was something very special about her."
Although the couple briefly split in 2007, they quickly reconciled and tied the knot in April 2011. Now seven years later, the Duke and Duchess of Cambridge are the picture-perfect couple and are the proud parents to three adorable kids: Prince George, Princess Charlotte, and Prince Louis.
"I was beautifully surprised when I walked into that room and saw her as she was sitting there. I was like 'OK well I'm really going to have to up my game,'" Harry told BBC about his first meeting with Markle.
In that same interview, the prince's fiancée revealed that they knew they were going to do whatever it took to make their relationship work. "It was just a choice. Very early on we realized we were going to commit to each other," she said.
The resurgence of Diana's love advice comes at an appropriate time, as Harry and Markle are set to say "I do" in less than three weeks' time. However, some fans are mourning the fact that Diana will not be in attendance.
But that doesn't mean Harry won't be including his mother in this milestone. In fact, the engagement ring he gave to Markle includes two diamonds from the late princess' jewelry collection "to make sure that she's with us on this — on this crazy journey together."
Likewise, William also proposed to Catherine using a symbolic oval blue sapphire ring, which was actually Diana's engagement ring.
More from HuffPost Canada:
Commenting on whether or not his mother would have liked Markle, Harry told BBC, "They'd be thick as thieves, without question, I think she would be over the moon, jumping up and down, you know so excited for me."
Also on HuffPost: