Enamel

In Byzantium

The art of enamelling evolved considerably in Byzantium, especially in the Meso-Byzantine period (tenth to twelfth centuries AD). This was due to a perfect mastery of the ‘cloisonné’ technique, which made enamelling into one of the most favoured of the decorative arts in the Middle Ages. Enamel was used in goldsmithing to set precious stones in jewellery, liturgical objects, book covers, icons, and to decorate horse saddles and sacerdotal dress. The literary sources, which provide more information than archaeological evidence, also mention the use of enamel in architectural ornamentation. There is, however, very little evidence for this, apart from the six Byzantine plates of the altar screen ‘Pala d'Oro’. Although it is believed to have come from the Monastery of Pantocrator, there remains some doubt as to the altarpiece's true origin. Enamels were produced for the aristocracy and were often offered as diplomatic presents. Byzantine enamels came to the West through exchanges and as spoils after the Fourth Crusade. They were highly prized and often copied, whilst in the East, Georgia turned enamelling into a major tradition. The enamels that have survived to the present day are estimated to account for 20% of Byzantine production[1]. Apart from a few rare exceptions in archaeological discoveries, such as the bracelets of Thessalonica and the treasure of Preslav (Bulgaria), these enamels have largely been reworked and incorporated into Western goldwork. The various plaques—they all have different dates and styles—that make up the sumptuous triptych of Khakhuli (Georgia), dating from the twelfth century, indicate that the reworking of enamels must also have existed in the East. The study of enamels is therefore a complicated and delicate affair, especially when they have been removed from the original works and transformed through reworking, restoration, or retouching.

Enamel is a vitreous material, comprising powdered glass, which is melted with lead and borax. This results in a clear glass that can be coloured by adding metallic oxides (cobalt oxide produces blue, purple red can be obtained from iron and magnesium, and white from tin). Heated in special high temperature ovens (600°–800°), the glass melts and fuses and adheres to its metal base; and solidifies on cooling. It is then ground and polished. Resistant and durable, enamel provides a perfect complement to shiny precious metals and gems, and is sometimes used as a substitute for them. In enamelling, colours can only be applied in layers, as the metallic content of the pigments prevents them from being mixed. The shine, transparency, and opacity of the enamel depend on the intensity and duration of the firing. Successive firings of transparent enamels in various colours could create nuances, but the colours are generally pure and distinct. The Byzantine enamels were produced on a surface of gold, an alloy of gold and silver (electrum), silver gilt, and later copper alloys.

In the ‘cloisonné’ technique, the enamel is fused onto a metal plate in little cells, whose cloisons are made of metallic strips or bands curved and soldered onto the surface of the object, using a preliminary drawing that's been incised or engraved with a dotted line. The use of moulds for fabricating the plates whose hollows were then filled with enamel seems to originate in the workshops of Kievian Russia[2]. The diminution of solidified enamel requires several firings to ensure that colour reaches the level of the cloisons. The surface of the object was thereby entirely covered with enamel, the wire contours appearing through the colours (Vollschmelz). From the mid tenth century, only the figures or decorative motifs were made in enamel and silhouetted against the golden ground, creating a strong contrast (Senkschmelz, or ‘sunken enamel’). More unusually, the enamel coats the surface of figures rendered in repoussé, as is the case on the icon of the archangel Michael in the treasure of Saint-Marc.

Specialists have different theories on the origins of Byzantine enamels. The continuity between Classical and Byzantine enamel, proposed by K. Wessel, was contested by D. Buckton, who made the distinction between enamel techniques of the Paleo-Christian and Meso-Byzantine eras to advance, with regard to the latter, the hypothesis of a Western, or more specifically Carolingian origin. In any case, there is a marked difference between the works prior to the restoration of the images (843) and those made during the Macedonian dynasty. Among the rare examples dating from the Paleo-Christian era are the medallion with a bust portrait of Licinia Eudoxia in the Cabinet des Médailles (French museum of antiquities), dating from around 450, and a similar medallion in Baltimore. Both were made according to the filigree enamel technique, which was common practice in the Mediterranean until the seventh century AD. There is some dispute as to the origin—they are either from Byzantium or the West— of a number of works, without inscriptions and decorated with vegetal and animal motifs, such as the Louvre medallion stamped with a griffin and the ewer of St. Maurice d'Agaune in Switzerland. Obvious similarities with the bracelets of Thessalonica and the diadem of Preslav would seem to indicate that they originated in the Empire. The votive crown of the treasure of Saint-Marc, inscribed with the name of Leo VI (886–912); the enamels of the chalice of the Roman emperor (I or II); and the Reliquary of the True Cross (Limburg) in the middle of the tenth century are among the magnificent creations of the Macedonian era, and enable us to identify many isolated enamels. The translucent green grounds that are typical of the ninth century and still much in evidence on the crown of Leo VI were replaced in the mid tenth century works by grounds in bright gold. The tradition continued until the fall of Constantinople in 1204, reinforcing the evolution towards a refined and expressive style, with agile and graceful figures, which despite the material’s rigidity, achieved the desired mannerist effects at the end of the twelfth century. The crown of Constantine IX Monomachus, representing the emperor between his wife and her sister surrounded by elegant personifications, marks this evolution. The Hungarian crown offered to king Géza I by Constantine X Doukas, and which most certainly dates from his reign (1071–1078), also provides an important reference point. It is a foretaste of the art that flourished under the Comnenus family, of which the enamels of the Pala d'Oro are the finest examples.

These works were definitely produced in an imperial workshop. Other workshops probably existed in Constantinople, as they did elsewhere in the Empire. There is little information about the workshops' activities and the status and training of the artisans, who are all anonymous. If one accepts that the bracelets in the Museum of Byzantine Civilization are of local origin, the enamel tradition at Thessalonica may go back to the ninth century. The relics of St Demetrius are most certainly of local origin. They date from the thirteenth century and are decorated with the effigy of the saint and the very precise image of his shrine[3]. The characteristically dark ground of these pieces seems to indicate that other works may originate in the Empire’s second city. Examples include the cross of Dumbarton Oaks (inventory No. 36.20) or the one found in the shrine of the Danish Queen Dagmar in Copenhagen. The close relations fostered between the Empire and the Kingdom of Kiev in the eleventh century, encouraged the transmission of Byzantine knowledge and tastes in Russia, where the cloisonné technique was combined with local goldsmithing traditions[4]. The aesthetic beauty of the enamel, distinguished by layers of bright colour and bold gold edges, perceptible in the ornamentation of some Byzantine manuscripts, is fully evident in the miniatures in the Miroslav and Ostromir Gospels. While several Georgian enamels are considered to be Byzantine in origin, this country with its wealth of mines and long tradition in metal working, developed significant local production—a great variety of shapes and objects were produced—until the end of the Middle Ages. Italy and Sicily also produced cloisonné enamel in the Byzantine tradition. This probably occurred before the thirteenth century, but the pieces produced weren't as fine as the Byzantine works with their saturated colours and the finesse of their cloisons. Lastly, a small group of opaque-coloured enamels on a bronze ground, with Arabic or Greek inscriptions, would indicate the existence of a workshop in Anatolia in the twelfth century. The arrival of the Seljuqs after 1071 hadn't destroyed the Byzantine traditions[5].

[2] H. Evans (ed.), The Glory of Byzantium, New York, 1996, No. 214 and 215.

[3] A. Grabar, ‘Quelques reliquaires de saint Demetrios and le martyrium du saint à Salonique’ (the reliquaries of St. Demetrios and his martyrion in Salonika), Dumbarton Oaks Papers 5, 1950, p. 3-28.

[4] Evans, H., (ed.), The Glory of Byzantium, New York, 1996, No. 209.

[5] Byzance. L’art byzantin dans les collections publiques françaises (Byzantium: Byzantine art in French national collections), Paris, 1992, No. 244.