Bracelets that once belonged to two of Europe’s most notorious women are set to go up for auction on Tuesday in Geneva.

The jewels, which are expected to sell for millions of dollars, were owned by the last queen of France, Marie Antoinette, and Britain’s Duchess of Windsor Wallis Simpson, and have seen high interest from collectors, according to Christie's auction house.

Antoinette’s two bracelets are made up of three strands of diamonds and contain 112 stones. Christie’s auction house has estimated that they could sell for between $2 million and $4 million.

“To find a historic piece that can be traced back over 200 years is incredibly rare,” said Max Fawcett, head of Christie’s jewelry department in Geneva.

The queen bought the bracelets in 1776, just two years after taking the throne with her husband King Louis XVI, according to Christie's.

With the French Revolution in full swing, Antoinette sent a trunk to the ambassador of the Austrian Empire for safekeeping in 1791. When it was eventually opened after she was beheaded in 1793, the bracelet was discovered and then given to Antoinette’s daughter, according to Christie's.

The bracelets will be joined at Tuesday's auction by a ruby and diamond bracelet that once belonged to the Duchess of Windsor.

Simpson, a twice divorced American, married the Duke of Windsor, the former British King Edward VIII, after he abdicated the throne in December 1936. Forced to choose between the crown and Simpson, he gave up his position less than a year after his father’s death.

The Duke of Windsor gave the bracelet, created by Cartier, to Simpson on the occasion of their first anniversary in June 1938 while they were living in France. It was inscribed by the former king, “For our first anniversary of June third.”\

“She was really influential figure that people looked to as an icon in the jewelry world,” said Fawcett. “She had an incredible jewels and when they do come up for sale, it’s something that collectors are looking for.”

After Edward’s abdication, his brother King George VI, the father of Queen Elizabeth II, took the throne.

The duchess’s jewelry collection was first put up for auction in 1987 after her death, where it sold for far more than originally estimated.

The auction house estimated that the ruby and diamond bracelet could sell for between $1.10 million and $2.19 million on Tuesday.

Jeweler Tobias Kormind believes that the rarity of jewelry with connections to royalty could lead to the bracelets selling for far more than the estimates.

“Being able to own a piece of history from someone you can read about in books is so powerful,” said Kormind, the managing director of 77 Diamonds. “If you can’t make history then the next best thing is to own a piece of it.”