Gates to Paradise: Metal doors of the 11th and 12th century

Doors are mostly made of wood; only in special cases are they made of bronze. In antiquity, for instance, this material was used for selected doors in temples or palaces. This tradition was consciously continued in the Middle Ages, particularly by the Church. Usually decorated with images of biblical scenes, the doors also had liturgical and ritual significance as they were considered to be the gates to paradise. The bronze doors still preserved today represent the only surviving complex of large bronzes from the European Middle Ages, most of them dating from the 11th and 12th centuries. From this period, 28 bronze doors have survived: 23 in Italy, three in Germany and one each in Russia and Poland. The production of these doors involved the use of various copper alloys, with the lost-wax process being employed for their creation. The doors could be cast as a whole, or individual metal fittings could be attached to a wooden support. Some of the doors have inlays of different materials, which enabled coloured depictions of biblical scenes or saints. Previous studies have paid little attention to the production process itself or the interaction between the material and the images. The GAPAMET project has enabled these doors to be examined in detail for the first time. Comprehensive material analyses of all the doors on site have enabled questions about their manufacture, the choice of materials, and their significance to be answered. This publication presents various aspects of the GAPAMET project and beyond, including contributions from participants in the 2023 project workshop in Verona. Particular attention is paid to the historical context, the characterisation of materials used in door construction, and the visualisation of material knowledge networks. Based on the results of the GAPAMET project, some of the authors` methods include: 1) Three- dimensional photographic recording of the doors, along with documentation of their relief structure, for further study. 2) Non-invasive chemical analysis to identify the alloys used. 3) High-resolution photographic documentation of the doors. The results presented here expand our understanding of the complex of large medieval bronzes, which are interconnected and whose material closely conveys the meaning of the representations. This is the first time that a significant number of chemical analyses of these doors have been presented. The editors are a team of internationally renowned experts: M. Mödlinger, an archaeologist and materials scientist, is an expert in metallurgy and ancient metalworking. J. Utz is an art historian who has been working on medieval doors since her masters thesis. H. Schlie is an art historian who focuses her research on the iconology of materials and techniques. M. Fera is an archaeologist who has experience of applying image-based documentation methods to material cultural heritage.