In her biography, Diana later mentioned that she faced criticism for her outfit that night. She’d worn leather pants, which didn’t sit well with the royal family.

Diana defended her choice, saying she wanted to appear the same age as the crowd she was with.

Almost 40 years on, the photo has finally been made public in a new David Bowie biography, featuring extensive material from photographer Denis O’Regan — including that once-hidden moment.

While the image no longer poses a risk to the royal family’s reputation, it highlights just how much effort went into controlling Princess Diana’s public image behind the scenes.