Gates of Paradise: metal doors of 11th-12th cent. churches

Doors are and were mostly made of wood; only in special cases were they made of bronze. In antiquity, for example, these were selected doors in temples or palaces. This tradition was consciously continued in the Middle Ages, especially by the church. Here, the doors, which were usually decorated with pictorial representations of biblical scenes, had also a liturgical-ritual significance, as they were as well regarded as 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 date to the 11 th-12th centuries. From this period, 25 bronze doors have survived: 20 in Italy, three in Germany and one each in Russia and Poland. All the doors have in common that they are made of different copper alloys, made by the lost wax process: they could be cast as a whole, or individual metal fittings were attached to a wooden support. Some doors have inlays of various materials that allowed the coloured depiction of different biblical scenes or saints. In the previous studies of the art history of the 25 doors, little attention was paid to the production itself and the interaction between the material and the images. Through comprehensive material analyses of all the doors on-site, it is now possible for the first time to answer questions about the manufacture, the choice of materials and the significance of the materials. The interdisciplinary project aims to 1) Characterise materials and techniques used in the construction of the doors; 2) Identify artists, and their specific alloys and techniques; 3) Visualize networks of material knowledge: Properties, affordance and the material iconology in image systems. Methods used include 1) three-dimensional photographic recording of the doors and documenting their relief structure for further studies; 2) non-invasive chemical analyses to identify the alloys used; 3) dendrochronological analyses to identify and date the types of wood used, providing important information about restorations, additions and the use of local woods; 4) metallographic and isotopic analyses on selected doors, providing information about material treatments after casting and the origin of the copper used. The data obtained expand our knowledge of the comprehensive complex of medieval large bronzes, which relate to each other and whose material communicates closely with the meaning of the pictorial representations. We reconstruct the production as well as the cooperation and networks of the individual craftsmen and patrons and thus shed light on an important chapter of medieval craft and art history.

Doors are and have always been made of wood, with metal being used only in special cases. In antiquity, for example, these were the doors of choice for temples and palaces. This tradition was consciously continued in the Middle Ages, especially by the Church. The doors, usually decorated with images of biblical scenes, also had a liturgical and ritual significance, as they were considered to be the gates to paradise. The copper-alloy 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. Nearly 30 copper-alloy doors have survived from this period: three in Germany, one each in Russia and Poland, and the rest in Italy. All the doors are made of different copper alloys and were produced by the lost-wax process: they could be cast as a whole, or individual metal fittings were attached to a wooden support. Some doors have inlays of different materials, which allowed the colourful depiction of different biblical scenes or saints. Previous studies of the art history of these doors have paid little attention to the production itself and the interaction between material and imagery. Through comprehensive material analysis of all the doors in situ, it is now possible for the first time to answer questions about production, choice of materials and the significance of the materials. The interdisciplinary project enabled the 1) characterisation of materials and techniques used in the construction of the doors; 2) identification of the artists and their specific alloys and techniques; 3) visualisation of networks of material knowledge: properties, affordances and material iconology in pictorial systems. The methods used included 1) three-dimensional photographic recording of the doors and documentation of their relief structure for further study; 2) non-invasive chemical analyses to identify the alloys used; 3) dendrochronological analyses to identify and date the types of wood used, providing important information on restorations, additions and the use of local woods. The data obtained thus extends our knowledge of the extensive complex of medieval large bronzes, which are interrelated and whose material communicates closely with the meaning of the pictorial representations. We reconstruct the production, cooperation and networks of individual craftsmen and patrons, shedding light on an important chapter of medieval craft and art history.