The Barbarossa Chandelier is one of the most famous medieval chandeliers in Europe and is one of the most impressive works of art in Aachen Cathedral. This work provides a detailed examination of the Barbarossa chandelier in Aachen Cathedral from historical, art-historical and technical perspectives. It begins by discussing the chandelier?s origins within the context of the Holy Roman Empire and its connection to Emperor Frederick Barbarossa. The authors then examine the architectural design of the ring-shaped crown, the towers, gates, inscriptions and symbolic references to the heavenly Jerusalem from the Book of Revelation. A significant section of the book is devoted to the decorative programmes, the reliefs, and the depictions of Christ, Mary, the apostles and the Beatitudes. In addition, attention is given to material analysis, the history of restoration, conservation techniques, gilding, structural reinforcements and the modern restoration works carried out. Numerous colour photographs, close-ups and technical illustrations support the text and document both the artwork and the restoration phases. (AI-generated content description)