If there were a contest for “biggest tiara in Europe,” I’d be hard pressed to think of another sparkler that could best this one. The Empire Tiara owned by the grand ducal family of Luxembourg is a massive diamond fortress of a tiara. At more than four inches tall, it’s a giant of the tiara world. Because of its size, the all-diamond tiara has plenty of room for the incorporation of numerous motifs, including geometric, anthemion, and scroll designs.

But even though it’s such a knockout, its provenance is a bit unclear. This tiara gets its name from its empire style, not because it came from imperial vaults. It’s an early nineteenth-century piece. For years, there were two major theories posited about how it arrived in Luxembourg. One traced it back to Romanov Russia via Grand Duchess Elizabeth Mikhailovna, the first wife of Grand Duke Adolphe. The other pointed to Adolphe’s daughter, Grand Duchess Hilda of Baden, who died without descendants and may have left jewelry to her nieces. But the ladies over at Luxarazzi have done some digging into the family’s jewel inventories, and they have ascertained that the piece was in the family’s possession by 1829 (because that year, the jeweler Jakob Tillman Speitz made alterations to the piece), making both of those previous theories impossible.

So the Luxarazzi ladies have posed a new theory: that the tiara was possibly acquired as a wedding gift for Pauline of Württemberg, who married Wilhelm, Duke of Nassau, in 1829. The German dukes of Nassau became the rulers of the grand duchy of Luxembourg in 1890, when salic law prevented Queen Wilhelmina of the Netherlands from ruling. (The two countries had been in a personal union; it’s similar to what happened when Queen Victoria was unable to become Queen of Hanover in 1837.) The tiara came with the new Grand Duke Adolphe to Luxembourg. It’s now mainly reserved for the use of the reigning grand duchess or the consort of a reigning grand duke.

It’s also twice been used as a wedding tiara by members of the family. In 1919, it was worn by Grand Duchess Charlotte to marry Prince Felix of Bourbon-Parma; they’re the grandparents of the current grand duke, Henri. Charlotte’s younger sister, Princess Hilda, also wore the tiara at her wedding to Adolf, the 10th Prince of Schwarzenberg, in 1930. The tiara was worn regularly by Grand Duchess Joséphine-Charlotte during the twentieth century, and today it is worn by her daughter-in-law, Grand Duchess Maria Teresa. She tends to bring out the tiara only for the grandest of occasions, and it’s easy to see why!