Cross of Lothair in the context of "Decorative art"

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 crux gemmata (Latin for jewelled cross) is a form of cross typical of Early Christian and Early Medieval art, where the cross, or at least its front side, is principally decorated with jewels. In an actual cross, rather than a painted image of one, the reverse side often has engraved images of the Crucifixion of Jesus or other subjects.

Examples in metalwork are the Cross of Justin II (6th century, in the Vatican Museums), the 'crumpled cross' in the Staffordshire Hoard (8th century), the Cross of Lothair (10th century, Aachen Cathedral Treasury), the Iberian Cross of the Angels (808) and Victory Cross (908), and the Cross of Cong (1120s?, National Museum of Ireland).

A processional cross is a crucifix or cross which is carried in Christian processions. Such crosses have a long history: the Gregorian mission of Saint Augustine of Canterbury to England carried one before them "like a standard", according to Bede. Other sources suggest that all churches were expected to possess one. They became detachable from their staffs, so that the earliest altar crosses were processional crosses placed on a stand at the end of the procession. In large churches the "crux gemmata", or richly jewelled cross in precious metal, was the preferred style. Notable early examples include the Cross of Justin II (possibly a hanging votive cross originally), Cross of Lothair, and Cross of Cong.