By the late Middle Ages, many kingdoms did have established royal regalia, that is, material symbols of monarchy that belonged to "the state" rather than to kings and queens as individuals. The most famous example of this is the Holy Crown of Hungary, whose possession was understood to legitimize the current king. Why is it so famous? Well, when King Albert died in 1439, he left behind a daughter and a pregnant wife. The Polish nobility, eager to plunder Hungary for their kingdom, were maneuvering to force widowed Queen Elisabeth into marriage. Hoping against hope for a son, Elisabeth held out. When she did deliver little Ladislaus, she conspired with her lady-in-waiting Helene Kottaner to steal the crown. Kottaner actually recorded her account of the crown heist--I don't know why we don't have a blockbuster movie of this yet. It even involves a castle nearly burning down. Anyway! With the official state crown in hand, Ladislaus was able to be crowned king.

You'll notice something, of course. He's an infant. The crown isn't to be worn regularly or even occasionally--it's to be present at the ceremony, a tangible symbol of the connection to the kingship.

And that's what we find in other kingdoms, some of which had specific crowns passed down from monarch to monarch but rarely with the same almost supernatural importance assigned to the Hungarian one. Crown-wearing was an activity limited to very specific occasions--coronation, wedding, major feast days, knighting ceremonies for the most important young noblemen...or Frederick Barbarossa parading into the church in the Jerusalem he'd negotiated from Saladin, donning the crown as King of Jerusalem basically to anger the pope. And yet it was typical of kings and queens to possess a whole host of crowns, some made specifically for them, some inherited from a parent or relative. If one didn't fit, well, there were plenty more whether that came from--Isabella of France received twelve crowns as gifts on her wedding day alone.

There was nothing specifically "royal" about crowns like these, except when they were in the possession of the monarch. Blanche of Navarre, queen to Philip VI of France very very briefly in the 14th century (he died fast), willed eight crowns to her goddaughters--including one that, her will notes, she lent out to female friends to wear at their own weddings.

And, interestingly, there was nothing particularly gendered about individual crowns, either. Philip willed all of his crowns except for one to Blanche; the one he reserved for his son had sentimental value, since Philip had worn it to John's knighting. And Philip's first wife, Jeanne, split her crowns between her son and her daughter.

But her daughter got all her books.