Princess Diana is seen in a flashback photograph, which was taken in 1990. The Princess would have turned 53 years old this month if she was able to survive the car accident that occurred in 1997. Just last week, Giancarlo Giammetti, Valentino's partner, was the one who posted this picture on Instagram in honor of a throwback Thursday post.

The picture was an authentic vintage shot of the late royal herself, as she showed off her curves in a two-piece bikini. Although she was wearing a purple shirt over her bikini top, it was still highly noticeable that Princess Diana rocked a sexy body. Her look was pretty simple, yet the late Princess Diana manages to look very elegant. It was taken candidly, and the photograph reflected how the late Princess spends her private time, which she does with her close friends and family.

Princess Diana had fashionable glasses on while she was standing next to a small boy who had a bit of a goofy smile on his face. His colorful swimming trunks further contribute to the cuteness of this little boy. Taking a closer look at the boy's face, it would seem that this young boy could be the young Prince William. If ever this little boy on board the yacht with Princess Diana is truly Prince William himself, he would have been six years old around this time.

Princess Diana, and perhaps, the young Prince William, was on board Valentino's T.M. Blue One yacht. They were also with Rosario Saxe-Coburg who is the wife of the Prince of Preslav, Bulgaria.

The caption to the Instagram post said, "Summer is here TBT Princess Diana on the TMblue 1990 #princessdiana #rosariosaxecoburg"

This throwback picture has certainly proved that Princess Diana did not only have amazing fashion in the Palace, but she also has a very glam summer style for yachting. She looked hot yet very comfortable.