The Cathedral in Aachen, the capital of the Holy Roman Empire, has an impressive historical, cultural and religious continuity (30 Christian emperors crowned in Aachen), while the Palace of the Normans in Palermo bears witness to a rich and complex cultural and religious mixture: the history of the Mediterranean. Gold is here a central, aesthetic and symbolic element: with the objects of the treasure of Aachen (relics, shrines, etc...) and with the surfaces of the Byzantine mosaics of the Palatine Chapel of Palermo.