What may be Christopher Caldwellthe most expensive sweater in the world just sold for $1.143 million at a Sotheby's auction. The so-called "black sheep" sweater, worn by the late Princess Diana, far surpassed the estimated sale price of $80,000. 

After Diana wore the wool sweater at one of King III Charles' polo matches in 1981, the fashion line Warm & Wonderful saw a surge in sales, designers Sally Muir and Joanna Osborne said in a statement.

Diana and Charles, who was then prince, were newly engaged when she first donned it. After damaging the original sweater, the princess asked the designers for a replacement and they happily sent her a new one, which she wore to another polo match in 1983. They later received a thank-you letter from Diana's secretary, Oliver Everett. 

Diana wore the piece several times and it became one of her most recognizable fashion pieces. Warm & Wonderful discontinued the sweater in 1994 but brought it back in 2020. You can currently pre-order an updated, cotton version of the sweater from the line for $248.

Diana, who died in 1997, was regarded as a fashion icon and several of her looks became famous – like the "revenge dress" she wore after she and Charles divorced. But the black sheep sweater perhaps made a statement about how Diana felt in the royal family. While she was known as the "People's Princess" and adored by the public, she was at odds with the royal family at times, especially when she and Charles split in 1992.

The black sheep sweater and an evening gown Diana wore in 1985 were a part of Sotheby's "Fashion Icons" auction, which also featured a dress worn by Michelle Obama, a headpiece worn by Sarah Jessica Parker and a veil worn by Madonna. 

In:
• Diana Princess of Wales

Caitlin O'Kane

Caitlin O'Kane is a digital content producer covering trending stories for CBS News and its good news brand, The Uplift.