Fragment of San Giovanni Fuorcivitas church chair

This fragment was an ornament on the parapet of the stairs of the chair of Saint-Jean-hors-les-murs church in Pistoia (twelfth century), created by Guglielmo. The comparison of this chair with its contemporary equivalents created by the Pisano Brothers in Pisa (Baptistery, 1260) or even Sienna (Duomo, 1268) which have a resolutely western style, reveals the strong oriental impregnation in the work of Guglielmo.

A network of white marble enclosing small squares of glass. The overall composition is geometric: six-pointed stars give birth to complex patterns. This decorative design is very well known in Islamic art and is displayed on different items[1], in different eras. It was particularly well developed in decorative arts from the Mamluk dynasty (1250-1517) which reigned over Egypt and Syria at the time when this chair was made. Overall, it calls to mind wooden Mamluk doors encrusted with pieces of ivory, which the Musée du Louvre possesses several examples of. Two door panels[2] in particular take up this principle of geometric cutting of the surface and display on their backs a panel where white ivory is used to frame dark patterns in wood.

The glass elements, gilded on the back, are cut with vegetal motifs (furls, half palm leaves), geometric patterns (bands alternating hexagonal and triangular shapes) and animal motifs (birds facing each other). The motifs belong to the repertory in fashion in Venice in the thihteenth century[3], particularly in the gothic style illuminations. It is interesting to note that these same motifs were used in Islamic art from the Omeyyad era (661-750).

If it was not Giuglielmo himself who made the glass parts, it was probably a craftsman from the laguna who was entrusted with the work. Venice was the only Italian city at the time in permanent contact with the Muslim world via its intense trade activity which enabled privileged cultural exchanges. The taste for glass objects of oriental inspiration was well developed there from this period[4], and it was from the Orient that raw materials necessary to the expansion of the famous Venetian glassworks were imported[5].

Eglomisé glass has been known since Roman antiquity. In the Islamic world, the closest technique known since the tenth century is that of “sandwich” glass, which consist of applying a golden decoration between two layers of glass[6]. The decoration of the qibla wall of the Mamluk mausoleum of Ahmad ibn Sulaymân al-Rifa’î in Cairo (1291) displays painted squares under glass inserted in stucco. This mausoleum is remarkable: it is the most relevant point of stylistic and technical comparison in the study of the chair of Pistoia. Virtually contemporary, the two ensembles display the same disposition of glass squares ornamented on the back and inserted into a geometric composition.

Painting under glass is still used to this day in the Mediterranean Muslim world for the production of real little popular art paintings[7]. The rise of these objects should be associated with the development of this technique in central Europe from the seventeenth – eighteenth centuries. The technique was probably transmitted via Balkans art, the Balkans being a province of the Ottoman Empire until the twentieth century.

[2] OA 7463 A and B.

[3] See for example the half palm leaf motifs in the Apparatus in Decretales, fol. 005 et 197v, 1260-1280, Avranches museum.

[4] The production of so-called “Aldrevandin” goblets is one of the manifestations.

[5] Archive documents give evidence of this trade: in 1277, a treaty was signed between the Venetian government and the prince of Antioch putting in place a tax for the purchase of cullet (broken glass) by the Venetians.

[6] Cup fragments, blue and gold enamel in sandwich glass, Syria or Iran, tenth century, Copenhagen, Davids Samling, inv. 4/1987.

[7] Pilgrimage to Mecca, painting under glass by Abu Sobhi al Tînawi, Syria, Damascus, 2nd half of the twentieth century, Marseille, Musée des Civilisations de l’Europe et de la Méditerranée.