Princess Diana's fashion always seemed to have been chosen carefully and with a clear message. 

But some outfits only gained importance after she went public with her marriage problems and difficulties with the Royal Family. Today, we see a wool sweater of the Princess of Wales with completely different eyes.

Princess Diana: The "black sheep" sweater

In 1983, Diana accompanied her then husband Prince Charles and his sister-in-law Sarah Ferguson to a polo match. There, she appeared in a red sweater by Muir & Osborne. It features rows of white sheep — except for one. One was a black sheep.

Prince Charles and Lady Diana at a 1983 polo tournament

The young woman at Prince Charles's side was only 21 years old and already seemed to be sending messages through her fashion. Three years earlier, in 1980, Diana appeared at an event in the same top.

Her relationship with the heir to the throne began that same year. Only later did she speak openly about how difficult her time as a royal had been.

Lady Di: The meaning of her famous sweaters

The princess was plagued by marital issues with the unfaithful Charles. She had to raise her two children in public and struggled with mental health problems and bulimia for years. Perhaps this sweater already showed Diana's discomfort in her role.

But the message only became clear years later. In 1995, she said in her legendary BBC interview: "I don't think many people will want me to be queen. Actually, when I say many people, I mean the establishment that I married into." 

She felt like an outsider, the black sheep of the Royal Family. It was this black sheep that graced her red sweater years earlier. So it was as if it was made for Diana — but not quite.

As the two designers of the brand, Sally Muir and Joanna Osborne, explained to People, the princess didn't buy the sweatshirt in their shop and it was also not specially designed for her.

"Black Sheep": Princess Diana's Sweater Spoke Volumes

They suspected the item of clothing must have been a gift that Diana simply liked. "She has a wonderful sense of fashion, and our sweater is perfect for her casual style," the designers explained at the time.

With this sense of fashion, Lady Di will never be forgotten. We remember the infamous story behind the 1994 revenge dress. The People's Princess carried her feelings outward through fashion — and that was already a fact with her sweater from 1983.