This name allowed Napoleon to compare himself to the famed medieval monarch Charlemagne, King of the Franks and Holy Roman Emperor.
When Napoleon declared himself Emperor of the French a decade later, he decided to create new imperial regalia, the centrepiece of which was his "Charlemagne crown".
To make this more credible, this publication claimed to have been published for the first time at the end of the Reign of Terror, like the crown had survived the Revolution.
They are set with shell cameos and carved carnelians which meet at a golden globe, on top of which is placed a cross.
Only a handful of crowns were kept for historic reasons, and they had their precious jewels replaced in them by decorated glass.