On the Tables of Roman Emperors, Soldiers and Commoners - Ribbed Glass Bowls



Featured here from the broad and diverse glass artefacts in the holdings of the Roman Period Collection of the Archaeological Museum of Istria are ribbed glass bowls. The specimens shown here are a sample of the ribbed bowls kept at the museum.

This form of glass tableware, developed in imitation of older metal and glass vessels, was very popular in the first century period as is evident from the great number of recovered specimens across and outside the bounds of what was once the Roman empire. Their broad popularity is certainly attributable to advantageous characteristics such as the suitability of this sturdy and thick-walled form for commercial transport.

Early examples were made of the polychrome, mosaic glass that was in great demand in the first half of the first century among the upper classes of Roman society. Equally cherished in this period were luxury specimens done in richly coloured monochromatic glass. The period of the Flavian dynasty saw a shift in popularity towards naturally coloured glass and saw production move almost exclusively towards this group of ribbed bowls. They were used less extensively in the second century and were only sporadic finds in third and fourth century contexts.





In terms of typology the selected specimens of ribbed bowls are of the Isings form 3, most prevalent in the current literature. This typological classification, proposed by archaeologist Clasina Isings, shows the basic morphological characteristics and variants. Her typology, thus, also identifies the 3a and 3b variants, i.e., the shallow and deep bowl.

The forms of this group of bowls are characterised by a number of shared attributes. The basic form is that of a hemispherical body with an outer surface decorated with moulded ribs running from the rim to the base. The number of ribs varies. The rim is straight or slightly everted with a clean cut lip, while the base is flat or slightly concave. The interior of the receptacle varies from finely to coarsely worked. The interior and rims of luxury specimens are ground and polished, with engraved lines decorating the interior face of the vessel wall.




From the earliest studies of ribbed bowls there has been a debate concerning the method of fabrication. Open forms, such as ribbed bowls, were made using the sagging process. The dominant hypothesis today was that the shaping of the ribs involved the use of glassmaking tweezers. The heated walls of the glass disc were pinched with tweezers at regular intervals. The ribbed disc was then placed on a convex mould and reheated to achieve the final form. The final phase, following the cooling of the vessel, involved grinding, polishing and the engraving of some parts of the receptacle (rim, interior surface).

For the production of ribbed bowls done in the mosaic technique the above-described process was preceded by a complex and lengthy stage. This involved fabricating multicoloured glass canes. These were then fused to form the desired mosaic pattern and heated. In this manner stretching reduced the patterns, later cut into smaller pieces. The thus processed pieces were then placed on a flat surface to form a disc and heated until all the parts were fused. This was followed by the process of forming the ribbing.




The mosaic technique: the fabrication process (from: Wight, 2011)




The process of fabricating ribbed bowls (from: http://www.theglassmakers.co.uk/archiveromanglassmakers/poster03.htm)




The primary function of ribbed bowls was as tableware. Their form was suitable for the serving of food. The relatively thick and sturdy walls of the vessel made them suitable for transport over great distances. The great popularity of these vessels in the early imperial period has seen them recovered in a range of contexts. At times they were used for funeral rites as grave goods or as lids for ceramic urns.

They were solid items (with thick and robust walls, a compact form suitable for transport, etc.) and have also been recovered in military camp and fortification contexts.




Among the ribbed bowls we see a level of homogeneity and some differences in morphological characteristics. This exhibition features six specimens of ribbed bowls selected so that we may consider their specific attributes. The primary differentiating criteria in this case are glass colour and decorating technique.



Polychrome ribbed bowls

This group includes ribbed bowls done in a mosaic technique that imitates marble or semi-precious stone. Two specimens are presented from the museum holdings with spiral decoration done with opaque white glass incorporated into a purple and amber yellow base.

Bowls of polychrome glass are high quality and meticulously crafted products of early imperial glass workshops. The aspiration towards luxury is evident in the work of the master glassmakers aimed at attaining a product that as realistically as possible imitated precious and semi-precious stone. The quality of the fabrication is reflected in the working of the interior surface, finely ground and polished, with precisely engraved linear decoration, while the exterior surface is characterised by meticulously worked rims and precisely formed ribs.

The first selected specimen (catalogue no. 1) is a fragment of a bowl of purple glass decorated with white spirals for which we do not have data on the circumstances of its discovery. Although the bowl is fragmented and only a part of the base and the lower part of the ribbing has been preserved, the morphological attributes show the work of the very best master glassmakers characteristic of polychrome receptacles.

The fragment of a bowl of amber yellow glass with white spirals (catalogue no. 2) was found during archaeological investigation in the area facing the amphitheatre in Pula in 2008. The receptacle exhibits morphological characteristics typical of polychrome specimens. It is a luxurious early imperial product dated to the early first century on the basis of the other finds in the stratigraphic layer from which it was recovered.

We find parallels for these bowls at many European sites, primarily in Italy. Individual finds have been recovered at eastern Mediterranean sites and the shores of the Black Sea. Notably, polychrome bowls are also found outside the bounds of what was once the Roman empire, from the Middle East to China. A significant number of polychrome ribbed bowls have been found in Croatia, most in the broad area in and around Zadar and at sites in the Istrian peninsula; at Salona, Narona and Siscia and the military camp sites of Burnum and Tilurium.

The production of this group of polychrome ware is dated roughly to the period from the end of the first century BCE to the mid-first century CE.





Brightly coloured monochrome ribbed bowls

The second group of ribbed bowls includes brightly coloured monochrome receptacles, usually cobalt blue, amber brown, olive green or purple. In terms of the quality of their fabrication they are comparable to the polychrome bowls and are characterised by a finely finished interior surface, evenly spaced ribs on the outer surface and a finely ground and polished rim.

The bowls selected from the holdings are of amber brown colour in shallow and deep variants (Isings 3a and 3b), recovered from a single grave at the Pula necropolis in 1935. The grave, which held a modest inventory of grave goods, included a broken ceramic urn that contained a glass olla with a lid and a pair of balsamaria. The glass bowls were included as grave goods next to the urn. The shallower bowl (catalogue no. 3) has been partially reconstructed and is characterised by a meticulously finished interior with engraved lines at the base and along the lip of the rim. The ribs are regular in form, shallow and evenly spaced and have been ground at the part that meets the rim, also ground and polished. By its morphological characteristics this specimen is numbered among the high quality early imperial Italic products.

An almost entirely preserved deep bowl (catalogue no. 4) is missing small parts of the base and body, which have been reconstructed. It is characterised by a ground and polished interior with engraved lines and a ground rim. The glass and finish are of somewhat lesser quality than the previous specimen.

Brightly coloured monochrome bowls have been found at many antiquity period sites. They are associated with the eastern and western provinces of the empire, with a somewhat greater concentration in the west, in particular on the Apennine peninsula and at civilian settlements and military encampments of the limes along the Rhine and Danube rivers. They are only sporadically found in the eastern Mediterranean and Black Sea area, and there have been finds outside the bounds of the Roman empire. In Croatia the greatest concentration of finds is in the southern Liburnian area (Zadar and its broader environs).

Judging by their broad distribution and the observed particular features of these receptacles it appears that multiple glass workshops were contemporaneously active in the east and west.

These vessels were in use from the early to the second half or end of the first century, when their production ceased.





• Naturally coloured monochrome ribbed bowls

The final group of bowls are characterised by natural glass colour and, overall, a somewhat poorer quality of workmanship (traces of tooling, lack of uniformity in the final appearance and so forth). Although specimens of lesser workmanship are numerically dominant among the naturally coloured bowls, there are also specimens of higher quality (finely worked interior with engraved lines, precisely formed ribs, etc.).

Two fragmented bowls have been selected from the museum holdings, recovered in the course of the rescue archaeological investigation of the Portarata site in Pula in 1995 and dated to the first century. A shallow ribbed bowl (catalogue no. 5) preserved in fragments is characterised by finer workmanship evident in the finish of the rim, ribs and interior surface. The morphological characteristics of a deep bowl (catalogue no. 6) are consistent with the simpler forms typical of this group of receptacles.

Naturally coloured ribbed bowls are the most prevalent group of this vessel type, and have been found in great numbers at sites across and outside the bounds of what was once the Roman empire. They are particularly frequent finds in civilian and military settlements and the forts along the Danube and Rhine river limes. Many have been recovered at sites across Croatia.

The great quantity of broadly distributed naturally coloured ribbed bowls, and some of the characteristics of comparable specimens, suggest that multiple and contemporaneous glass workshops were active in both the east and west (Roman Italia) of the empire. The height of production occurred throughout the whole of the first century and they were especially popular during the period of the Flavian dynasty, marked by an increased number of local glass workshops in the west. Their prevalence dropped in the second century, with sporadic specimens dated to the third and fourth centuries.

The production of ribbed bowls began in the eastern Mediterranean near the close of the first century BCE, but Italic glass workshops quickly took the leading role. In the first half of the first century the glass workshops on the Apennine peninsula distributed great quantities of this type of tableware across the Roman empire. Their great popularity saw the production of naturally coloured ribbed bowls spread to glass workshops in the western provinces—in particular Gaul and the Rhine area—in the second half of the first and early in the second century. In the centuries that followed we only see the use of naturally coloured bowls, found sporadically in third and fourth century closed contexts.





Based on analogues of similar typological and morphological characteristics we can posit that the presented specimens are the products of first century Italic glass workshops.

All this points to the conclusion that there was intensive commercial exchange between the Istrian peninsula and the neighbouring Italic area during the period that saw the greatest popularity and production of ribbed bowls. Further supporting this conclusion are the many unpublished fragments of ribbed bowls kept in the holdings of the Archaeological Museum of Istria.





1. Fragment from the base of a polychrome ribbed bowl of purple base colour decorated with white spirals. Five ribs are partially preserved. Two engraved lines are visible on the interior face at the transition from the base to the body, and a small circle at the centre. The base is slightly concave.
Inventory code: A-5946
Site: unknown
Dimensions: length: 3.8 cm; width: 5.9 cm; thickness of the base: 0.6 cm
Date: 1stC BCE (late)–1stC CE (mid)



2. Fragment of the rim and a part of the body of a polychrome ribbed bowl of amber yellow base colour with white spirals. Three ribs are partially preserved. Evident traces of grinding and polishing on the outer face of the rim, the ribs and the interior face. Engraved line on the interior face under the rim. Traces of iridescence.
Inventory code: A-31178
Site: Pula, Block 70 facing the amphitheatre
Dimensions: height: 4.8 cm; width: 5.8 cm; thickness of the wall: 0.55 cm
Date: 1stC (early)




3. A shallow bowl (Isings form 3A) of amber brown colour decorated with 34 closely spaced ribs in relief. The vessel has been partially reconstructed. Evident traces of grinding and polishing on the exterior face of the rim and at the tops of the ribs. Shallow engraved lines visible on the interior face where the body transitions to the base and under the rim. A small engraved circle at the centre. The base is slightly concave.
Inventory code: A-4897/a
Site: Pula, Vodnjanska ulica; necropolis (1935)
Dimensions: height: 4 cm; diameter: 15 cm
Date: 1stC



4. A deep bowl (Isings form 3B) of amber brown colour decorated with 30 closely spaced and uneven ribs in relief. The vessel has been partially reconstructed. Evident traces of grinding and polishing on the exterior face of the rim and at the tops of the ribs. Shallow engraved lines visible on the lower part of the interior face of the body and at the rim.
Inventory code: A-4897
Site: Pula, Vodnjanska ulica; necropolis (1935)
Dimensions: height: 5.6 cm; diameter: 12 cm
Date: 1stC



5. Nine fragments of a shallow ribbed bowl (Isings form 3A) of naturally coloured, bluish glass. Parts of the rim, body and base are preserved. The ribs are prominent, thin and tooled where they meet the rim. The exterior face of the rim and the interior are ground and polished. There is a pair of engraved lines on the interior face at the transition from the body to the base.
Inventory code: A-49954
Site: Pula, Portarata (1995)
Dimensions: height: 4 cm; diameter (reconstructed): 14 cm
Date: 1stC



6. Five joined fragments of a deep ribbed bowl (Isings form 3B) of naturally coloured, blue-green glass. Parts of the rim, body, base and of six uneven ribs are preserved. The exterior face of the rim and the interior are ground and polished.
Inventory code: A-49955
Site: Pula, Portarata (1995)
Dimensions: height: 7.5 cm; diameter (reconstructed): 16 cm
Date: 1stC




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On the Tables of Roman Emperors, Soldiers and Commoners - Ribbed Glass Bowls


 Carrarina 4, Pula
 Window to the Past
26. 4. – 26. 7. 2021.

Exhibition and text author:
Aska Šopar

 Organizer and publisher: Archaeological Museum of Istria

For the organizer and publisher: Darko Komšo

Editorial Board:
Darko Komšo, Adriana Gri Štorga, Irena Buršić

Set up & graphic design:
Vjeran Juhas

Exhibition coordinator:
Monika Petrović

Vjeran Juhas

Ivo Juričić

Restoration by:
Monika Petrović

Translation in Italian:
Elis Barbalich-Geromella

 English translation:
Neven Ferenčić

Irena Buršić, Giulia Codacci-Terlević,
Adriana Gri Štorga, Aska Šopar, Milena Špigić

Print: MPS Pula

Print run: 500

Pula, 2021.



Typo3 site by Ulisys d.o.o. , 2010.