1 of 6
The family of four poses together at their countryside home, Highgrove. Prince Charles and Princess Diana were revolutionary when it came to how they raised their royal sons. Prince William and Prince Harry experienced plenty of firsts for royal children, including attending pre-school outside of the palace and riding the London Underground.
2 of 6
One of very first firsts came just nine months after William was born, when he accompanied Charles and Diana on an official tour to Australia and New Zealand — against the Queen's advice.
3 of 6
One of Harry's most treasured and "very, very happy" memories with his mother was their trip to Disney World in 1993. "I went on Space Mountain 14 times," Harry told Good Morning America. Here, he slides down a water ride with Diana at the U.K.'s Thorpe Park.
4 of 6
The princes even got to meet Santa at London's Selfridges department store — though they waited in line like the rest of the children. "It was obvious she wanted her sons to be treated like other children," Alison Morris, a fellow shopper, said.
5 of 6
Diana died in 1997 in a tragic car accident in Paris. Ten years after her death, Harry confessed that the fact that his time with his mother was cut short continued to wear on him. "It still upsets me now, the fact that we didn't have as much of a chance as other children to spend time with her," he said in 2007. "But the time we did spend with her was amazing."
Everything Handsome Harry Has Been Up to at the 2017 Invictus Games in Toronto
Why Seeing Prince Harry Hold Hands with Meghan Markle Is Such a Big Deal
Everything You Need to Copy Meghan Markle's Chic Style
12 Outfits Meghan Markle Wore on Suits That Will Give You Serious Workwear Inspiration