Hoop crown

A hoop crown (German: Bügelkrone or Spangenkrone,Latin: faislum),arched crown, or closed crown, is a crown consisting of a "band around the temples and one or two bands over the head". First used by the Carolingian dynasty, hoop crowns became increasingly popular among royal dynasties in the Late Middle Ages, and the dominant type of crown in the Modern Era.

Hoop crowns were introduced to Germanic Europe by the Carolingian dynasty, who usurped the throne of the Frankish Empire from the Merovingian dynasty in early medieval Europe. However their use dates back to the end of the Roman Empire and the Byzantine Empire. The Carolingian hoop crown was most probably derived from the contemporary Germanic hoop helmet (German: Spangenhelm). The oldest such crown is the Crown of Saint Faith in Conques, worn either by Pepin I (797–838) or Pepin II (823–864) of Aquitaine. Other Carolingians known to have worn hoop crowns are Louis II "the German" (806–876), Charles II "the Bald" (823–877) and Odo of Vermandois (910–946).Charlemagne (742–814) possibly wore a hoop crown, although the obscurities of contemporary portraits, in particular on seals, mean that this cannot be stated with certainty. Sometimes, the Carolingian hoop crowns were combined with a cap, worn beneath.

...
Wikipedia