Bust of Charlemagne in the context of Metalwork

The Aachen Cathedral Treasury (German: Aachener Domschatzkammer) is a museum of the Roman Catholic Diocese of Aachen under the control of the cathedral chapter, which houses one of the most important collections of medieval church artworks in Europe. In 1978, the Aachen Cathedral Treasury, along with Aachen Cathedral, was the first monument on German soil to be entered in the List of UNESCO World Heritage Sites. The treasury contains works from Late Antique, Carolingian, Ottonian, Staufen, and Gothic times. The exhibits are displayed in premises connected to the cathedral cloisters.

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.