When Prince Philip proposed to Queen Elizabeth II in the summer of 1946, after getting an enthusiastic blessing from her father, King George VI, he did so with one of the most iconic engagement rings in existence today.

The future queen quickly accepted her beloved husband-to-be’s proposal piece, which consisted of a three-carat center stone flanked by 10 additional diamonds (embedded into raised shoulders) all set in platinum.

The ring, which the couple debuted to the world the following summer, was beautiful but also meaningful; the gemstones were sourced from a tiara that Prince Philip’s mother wore on her own wedding day. Everyone knew then that it was a ring for the ages—which begs the question, where, exactly, is it now?

In the time since Queen Elizabeth’s death on September 8, 2022, many have speculated about who the late monarch might have left her most treasured piece of jewelry to—in addition to the rest of her extensive trove, a mix of both crown jewels (which amount to over 100 objects and 23,000 gemstones, per the Historic Royal Palaces’ website; these are owned by the nation and, by default, King Charles) and her private collection (several outlets estimate this at around 300 to 400 pieces strong).

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“The key difference between the crown jewels and the queen’s private collection is that the private collection we know much less about,” Kate Nicholl, Entertainment Tonight’s royal expert, explained in 2022. “These are gifts that are given to the queen over her reign, but the crown jewels belong to the monarch. They stay safeguarded at the Tower of London for the nation, and when one monarch dies, the crown jewels are immediately passed to their heir.”

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Since the late queen’s engagement ring is not considered a crown jewel, understanding who would stand to inherit it is not widely understood. Though there was likely a “hierarchy” in place when it came time to divide Elizabeth’s private collection, says Nicholl, the public wouldn’t necessarily know who got what (unless, of course, royals were spotted wearing a telltale tiara during outings). According to Nicholl, Queen Camilla was first in line to select her picks, followed by Kate Middleton, the Princess of Wales, and Meghan Markle, the Duchess of Sussex; Sophie, the Countess of Wessex (who is married to Queen Elizabeth’s son, Edward) was probably also included, The Sydney Morning Herald reports.

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Selecting a few of the monarch’s favorite necklaces and bracelets, however, is very different than inheriting her prized engagement ring, which she wore constantly throughout her life; she was buried with her Welsh gold wedding band, an another accessory she never took off. It’s more than likely that a piece that special was left to someone outside of that aforementioned pecking order entirely: Queen Elizabeth’s daughter, Anne, the Princess Royal. This would become the third proposal piece in Anne’s collection (she received her first from her first husband, Mark Phillips, and the second years later from her current spouse, Timothy Laurence). As for what she would potentially do with it? It seems unlikely that she would pass the piece on to her older children; her daughter Zara Tindall tied the knot in 2011 and her son, Peter Phillips, is recently divorced. Their children, however, could be potential inheritors.

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If Queen Elizabeth’s engagement ring wasn’t left directly to Anne, it was likely returned to a secure vault for safekeeping; according to E! News, this hiding place is reportedly 40 feet below Buckingham Palace. In this scenario, we have another question to ponder: Will it remain there forever or will it be passed on to a senior royal in the making? Princess Charlotte seems like a likely candidate, when the time is right—but it’s possible that Prince George or Prince Louis might propose to a future bride with their great-grandmother’s keepsake. “Whoever gets to wear that ring is going to be very, very special, indeed,” Nicholl explained. “I would imagine, possibly, perhaps for Princess Charlotte. We’ll have to wait and see.”