Jose Luis Cuesta – Pool/Getty Images

After the abdication of King Juan Carlos of Spain, some of the jewels worn Queen Sofia, his wife, were automatically passed along to the country’s new queen consort, Queen Letizia. But most of the tiaras worn by Sofia are her personal property, including today’s sparkler, her diamond floral tiara.

Queen Sofia wears the tiara during a gala for the President of Algeria, 2002 (Carlos Alvarez/Getty Images)

For many years, it was assumed that this tiara was much newer than it appeared to be. Conventional wisdom about the piece said that it had been made in 1962 at the request of the then-ruler of Spain, Francisco Franco, who gave it as a gift to Princess Sophia of Greece and Denmark on her marriage to Prince Juan Carlos of Spain. The jewelry house of Mellerio dits Meller was often put forward as a possible maker of the piece. Lots of people even still call this the “Mellerio Floral Tiara” — but Mellerio wasn’t involved in its creation at all.

Queen Sofia wears the tiara at a gala for the President of Lebanon, 2009 (DOMINIQUE FAGET/AFP/Getty Images)

The Spanish court has confirmed that Franco purchased an antique piece for Sofia rather than commissioning a new one. The tiara was made in 1879 by a British jewelry firm, J.P. Collins, for King Alfonso XII of Spain. It’s a convertible sparkler, able to be worn as a necklace or broken up into a series of brooches. Three five-petaled diamond flowers are connected by a garland of diamond leaves and foliage, giving the tiara a classic, timeless appearance. The piece was a gift from King Alfonso XII for his new bride, Archduchess Maria Christina of Austria. The tiara stayed with the family for more than half a century, but when they went into exile in the 1930s, it was sold. Franco was later able to acquire the piece, and his gift for the new Spanish princess managed to reunite a lost royal tiara with its original owners.

Infanta Cristina wears the tiara on her wedding day, 1997 (DOMINIQUE FAGET/AFP/Getty Images)

The relationship between Franco and the future King Juan Carlos was complicated to say the least, but the tiara wasn’t exactly just from him — it was a gift to the bride from Franco on behalf of the people of Spain. Since the monarchy’s reestablishment in Spain, the tiara has been worn by all of the senior royal ladies: Queen Sofia, Queen Letizia, Infanta Elena, and Infanta Cristina, who even wore the sparkler on her wedding day in 1997.

Queen Letizia wears the tiara during the Dutch inauguration festivities, 2013 (Michel Porro/Getty Images)

In recent years, the tiara has been worn almost exclusively by Queen Letizia. Some have suggested that perhaps Queen Sofia has given the tiara to her daughter-in-law, but we have no way of knowing whether the tiara has been gifted or merely loaned. As you can probably imagine, a royal family that has suffered through multiple exiles is rather tight-lipped about their personal property; they don’t publicize many details about their jewelry, including who owns it and how much they have.

Queen Letizia wears the tiara at a dinner for the President of Peru, 2015 (Jose Luis Cuesta – Pool/Getty Images)

But as Letizia has continued to wear this lovely tiara even during her husband’s reign — and Sofia has basically stopped wearing tiaras in public altogether — I think it’s fair to say that it will continue to be a regular part of Letizia’s jewelry rotation. Letizia has been wearing more and more pieces of jewelry associated with her mother-in-law, so it appears that Sofia has unlocked her jewelry box and given her daughter-in-law free rein. (Or, given the people involved, perhaps we should say “free reign”? Ha!)