UNGUENTARIUM Cobalt blue and iridescent glass H. 11.5 x W. 6.5 cm Byzantine art, 4th-7th century Provenance European private collection, acquired on the English art market in 1990-2000 A blown glass unguentarium in intense cobalt blue, globular in shape with a narrow neck. The centre of the piece features a circular recess surrounded by a cruciform motif in relief, a decorative and symbolic element characteristic of early Christian and Byzantine glassware. The cross, obtained by applying glass threads or by moulding, bears witness to the Christianisation of Byzantine art and the probably liturgical or funerary function of the object. These small flasks were used to contain sacred oils (chrism), precious perfumes, balms or ointments used during religious ceremonies (baptism, anointing of the sick, funerals) or deposited in Christian tombs as symbolic offerings. Blue glass, a colour associated with the divine and celestial in Byzantine iconography, reinforced the sacred dimension of the object. The technique of blown glass, perfected under the Roman Empire, enjoyed a new lease of life in Byzantium, where workshops in Syria-Palestine and Alexandria produced high-quality liturgical and funerary glassware that was exported throughout the Christian Mediterranean world. The cruciform motif, ubiquitous in Byzantine art from the 4th century after Constantine's conversion, transformed the modest utilitarian bottle into an object of devotion. A Byzantine blue cobalt Unguentarium. 4th-7th century A.D. In blown glass of intense cobalt blue hue, globular or pyriform in shape with narrow neck. The piece features a central circular indentation surrounded by a cruciform motif in relief, a decorative and symbolic element characteristic of early Christian and Byzantine glassware. The cross, created by applied glass threads or molding, testifies to the Christianization of Byzantine art and the probably liturgical or funerary function of the object. These small flasks served to contain sacred oils (chrism), precious perfumes, balms, or unguents used during religious ceremonies (baptism, anointing of the sick, funerals) or deposited in Christian tombs as symbolic offerings. Blue glass, a colour associated with the divine and celestial in Byzantine iconography, reinforced the sacred dimension of the object. The blown glass technique, perfected under the Roman Empire, experienced renewed development in Byzantium where workshops in Syria-Palestine and Alexandria produced high-quality liturgical and funerary glassware, exported throughout the Christian Mediterranean world. The cruciform motif, omnipresent in Byzantine art from the 4th century after Constantine's conversion, transforms this modest utilitarian flask into a devotional object.