Princess Diana left behind a vast style legacy, and soon enthusiasts will be able to bid for one of her most famous looks.

The celebrated 鈥渂lack sheep鈥� sweater first worn by Lady Diana Spencer at a polo match in 1981 when she was engaged to the now King Charles III will headline Sotheby鈥檚 Fashion Icons auction in New York and online between August 31 and September 14.

The original sweater, which is expected to fetch US$50,000 to US$80,000 when it goes on sale for the first time ever, will be on display at the auction house from September 7, the start of New York Fashion Week, according to Sotheby鈥檚.

鈥淭his exceptional garment, meticulously preserved, carries the whispers of Princess Diana鈥檚 grace, charm, and her keen eye for fashion,鈥� said Cynthia Houlton, Sotheby鈥檚 global head of fashion and accessories, in a press release on Monday.

鈥淚t鈥檚 an honour to offer this historic sweater in our inaugural Fashion Icons auction, placing it in dialogue with other memorable and culturally important items of clothing,鈥� she added.

Artists Sally Muir and Joanna Osborne and their knitwear label Warm & Wonderful created the knitted, bold-red, wool crew neck, which is adorned with rows of white sheep and one black sheep on the front, in 1979.

Diana鈥檚 look went viral, popularizing the small clothing business. 鈥淢uch to our amazement, the first we knew of Lady Diana Spencer wearing the sweater was when we saw her on the front page of one of the Sunday newspapers,鈥� said Muir and Osborne in the release.

鈥淗er influence was impactful almost immediately thereafter, leading to a surge in sales and public awareness of our small label, for which we will be forever grateful,鈥� they added.

A few weeks after Diana鈥檚 first outing with the garment, Muir and Osborne received a letter from Buckingham Palace informing them that Diana had damaged her beloved sheep sweater (a small tear in one of the cuffs is visible in images supplied by the auction house) and politely requesting either a repair or replacement, according to Sotheby鈥檚.

black sheep sweater

The palace returned the sweater to the designers, who knitted Diana an entire brand-new one. The palace later sent the designers a letter of gratitude.

Diana was pictured wearing the new sweater at another polo match in 1982, according to the Warm & Wonderful website. In the photograph, the lone black sheep appears to be on a higher row of white sheep on the new sweater than on the original.

The original sweater was rediscovered in March this year by Muir and Osborne in their attic, according to Sotheby鈥檚. It had been tucked away in a small box beside a cotton bedspread.

The media have for a long time speculated over potential hidden meanings in Diana鈥檚 clothing choices, and in this instance, the release says the sweater prompted speculation about whether the princess felt a connection to the lone black sheep because of her complex relationship with the Royal Family. Others simply interpret it as a celebration of Britain鈥檚 countryside and agricultural history.

A version of the sweater is on display in the permanent collection at London鈥檚 Victoria and Albert Museum and, while Warm & Wonderful stopped producing the lone black sheep style in 1994, in 2020 it resumed making copies of the design, which are still available for pre-order online for £250 ($295).

A replica was also created for actor Emma Corrin, who played Diana in the fourth season of 鈥淭he Crown,鈥� the hit Netflix drama about the Royal Family.