The dress by Jacques Azagury, once owned by PEOPLE, was first worn by Princess Diana during a 1985 visit to Italy

The allure of Princess Diana is still strong, as proven by the hefty price tag attached to the royal’s latest dress up for auction.

Julien’s Auctions announced on Sunday that Princess Diana’s ballerina-length evening dress by Moroccan-British fashion designer Jacques Azagury that she wore in Florence, Italy in April 1985 and again to the Vancouver Symphony Orchestra in 1986, along with a matching illustration, sold for $1,148,080. The winning bid was 11 times its original estimate of $100,000.

The identity of the buyer is unknown.

The sale shatters the previous world record for the most expensive dress worn by Princess Diana to be auctioned. The previous record was set earlier this year when her purple evening dress by designer Victor Edelstein sold for $604,800.

According to Julien’s Auctions, “The dress with padded shoulder pads features a black velvet bodice with embroidered stars in metallic thread made from Jakob Schlaepher fabric with a two-tier royal blue organza skirt with a sash and bow. The ballerina skirt was the perfect nod to Diana’s love of dance and her being a patron of The English National Ballet.”

The dress was once owned by PEOPLE, purchased for $26,450 at the Christie’s of New York auction that Diana held shortly before her tragic death in 1997. PEOPLE loaned the ensemble to Kensington Palace for the “Fashion Rules” exhibit in 2013.

Princess Diana and Prince Charles in April 1985.Jayne Fincher/Princess Diana Archive/Getty

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In addition to the Azagury dress, a blush pink chiffon Emanuels blouse worn by Diana in her 1981 engagement portrait sold in the same auction for $381,000, nearly four times its original estimate of $80,000.

Princess Diana wore numerous dresses by Azagury in her life. Recently, five glamorous evening gowns identical to the ones designed by Azagury and worn by Diana were sold to a private collector in Los Angeles for an undisclosed sum.

Princess Diana in Florence in April 1985.Georges De Keerle/Getty

“The whole collection means a lot to me, and the only reason I am selling them is because as of five weeks ago, I retired,” Azagury recently told PEOPLE. “I really wanted people to keep enjoying these iconic dresses and ideally to keep the whole collection together.”

The retired designer added that Princess Diana was “always very excited by fashion, and she knew she would please so many people just waiting for her to come out in the next dress, whether they were waiting in the streets or watching her on the television. She took a long time making sure that everything was just right, choosing the right shoes and jewelry.”

Princess Diana’s dress displayed at Kensington Palace in 2013.John Stillwell/PA Images via Getty

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While Azagury is happy to share the dresses with the public, some of which come with sketches and personal handwritten notes from Princess Diana, he has held some sentimental items back for himself.

“One of the most precious things that I have is a framed picture that the princess sent me the morning she was leaving for France, from which she never returned,” he said.

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Princess Diana and Prince Charles in April 1985.Anwar Hussein/WireImage

Azagury arrived at his shop to find a member of her staff waiting with a parcel. “Inside was a framed picture of Diana wearing three of the famous five dresses, with a message saying; ‘To Jacques, lots of love Diana’ — that I will be keeping all for myself,” he said.