All About Glass

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Glass in the Price Edict of Diocletian

All About Glass

In A.D. 301, Emperor Diocletian attempted to halt a rapid rise in prices by issuing his Edictum de pretiis (Edict on prices), which established maximum prices and wages throughout the Roman Empire. Copies of the edict were inscribed in Latin or Greek on marble panels and posted in prominent places. Fragments of one such copy, written in Latin, were found during excavations at Aphrodisias, Turkey, in 1970-1972, and they were published in 1973.1 These fragments include a hitherto unknown section of the edict: the prices of glass.

The text of the section on glass2 is as follows:

16, 1 De Vitro  
    1a Vitri Alexanḍṛịṇi libra una [X] viginti quattuor
     2 [Vitri I]udaici s virdis libra una [X t] redecim
     3 [Vitri Ale]xandrini in calicibus et vasis levibus in pondo una X triginta
     4 Vitri Iudaici in calicibus et vasis levibus in po(ndo) unum X vigint[i]
     5 Speclaris optimi libra una X octo
     6 Secondi libra una X sex


The text may be translated as follows:

16, 1. For Glass  
    1a. Alexandrian glass, one pound 24 denarii
     2. Judaean greenish glass, one pound 13 denarii
     3. Alexandrian plain glass cups and vessels, one pound 30 denarii
     4. Judaean plain glass cups and vessels, one pound 20 denarii
     5. Window glass, best, one pound 8 denarii
     6. Window glass, second [quality], one pound 6 denarii


In a commentary on this passage, included in the 1973 publication, the late Dorothy Charlesworth regretted that the text is "extremely vague and covers only a surprisingly limited range" of glasses.3 She took it for granted that Alexandrian and Judaean glass came from Alexandria and "the Sidon area" respectively, and she was puzzled by the fact that glass was sold by weight. She concluded that the words s(ub) vir(i)dis mean that Judaean glass was "natural green glass," and that the word levibus probably means that the vessels were plain.4 Believing that windowpanes were rather uncommon in the eastern Mediterranean in 301, Charlesworth wondered whether spec(u)laris refers to something other than window glass-another translucent material, perhaps, or even raw glass.

The text was discussed at greater length by Prof. Dan Barag in a paper delivered at the 10th congress of the International Association for the History of Glass in 1985 and published two years later.5 Barag took a rather more positive view of the text, and his opinions about it differed from those of Charlesworth on four points. First, he argued that the terms "Alexandrian" and "Judaean" refer to two different kinds of glass rather than to glass made in two different places. He did this largely on the grounds that Judaea ceased to be a Roman province in A.D. 135, when Hadrian made it part of Syria Palaestina. Consequently, Barag argued, Judaea had no place in an official document of 301. "Judaean glass," he suggested, was a trade name (or popular name) for glass of a certain quality: presumably common greenish glass. Second, he concluded that the distinction and differences in price between Alexandrian and Judaean glass on the one hand, and Alexandrian and Judaean cups and vases on the other, indicate that the former prices refer to raw glass while the latter prices pertain to glass vessels. Third, he suggested that the two kinds of spec(u)laris are probably varieties of window glass and not some other transparent material. Finally, Barag noted that glassware has been sold by weight in other times and places, and he argued that the statement that glass was sold by weight in 301 should be taken at face value.

Barag's last three points are as persuasive today as they were in 1985. We now know that a relatively small number of factories produced raw glass and supplied this to a very much larger number of workshops that turned it into objects. Many of the factories were located in Egypt and the Levant, and their products were traded all over the Roman world.6 This model of primary and secondary production owes nothing to the price edict (it was developed on the basis of archeological discoveries and chemical analyses), but it is entirely consistent with Barag's explanation of the two prices for Alexandrian glass and the two prices for Judaean glass in lines 1–4.

At the same time, 30 years of research has caused us to revise Charlesworth's view that Roman window glass was uncommon in the eastern Mediterranean. To give just one example of the quantity of window glass that was produced, a document of 326 records that the glazing of the heated room in the public baths at Oxyrhynchus, a relatively minor city in Egypt, required 6,000 pounds of glass, and E. Marianne Stern calculated that this was sufficient to make about 240 square meters of windowpanes.7 It is no longer necessary, therefore, to wonder whether the last items in a list with the heading De Vitro were made of some substance other than vitrum.

Similarly, it is entirely reasonable to sell plain glass vessels by weight, since the cost of producing them is directly related to the amount of glass they contain, and they did not require additional finishing. In any case, the Latin text is unequivocal.

The idea that vitrum Iudaicum may be taken literally to mean "glass made in Judaea," as Charlesworth supposed, receives support from the recent developments in our understanding of the Roman glass industry mentioned above. Indeed, as Caroline Jackson, Hilary Cool, and Emma Wager suggested in 1998, vitrum Iudaicum may refer to the provenance of the glass after all.8

Barag's main objection to the idea that vitrum Iudaicum was produced in Judaea in 301 was the elimination of Judaea as a province in 135. However, firm evidence exists for the continued use of the term "Judaea" after that date. It appears frequently in late Roman and early medieval literature. Admittedly, most of the references are later than 301, and the word usually occurs in biblical contexts and cannot be used as evidence that it was current at the time of writing. Some references, however, do indicate that Judaea continued to be a geographical term long after the publication of the price edict. Three examples may serve to demonstrate this. The Itinerarium Burdigalense, which was written in 333, refers to Judaea as a current geographical entity.9 In 406, Jerome wrote about the removal of the bones of Samuel from Judaea to Thrace by Emperor Arcadius (r. 383-402),10 and Isidore of Seville, writing not long before his death in 636, described Jerusalem as the center of Judaea.11 Judaea also appears on the Madaba Map, a mosaic on the floor of a church built in the second half of the sixth century at Madaba, Jordan.12 Thus, the name Judaea continued to be applied to part of the Levant for a long time after the province of that name had ceased to exist. It is unnecessary, therefore, to suppose that vitrum Iudaicum in the price edict refers to anything other than glass from Judaea.

Nevertheless, Charlesworth was mistaken when she concluded that Judaean glass came from "the Sidon area." Sidon was never in Judaea. It is approximately 90 kilometers north of the border that existed between Syria and Judaea before 135. However, at least two sites in Judaea are known to have produced raw glass in the Byzantine period, and it is reasonable to assume that the region also produced glass at the time of the price edict. At Bet Eli'ezer, excavations revealed the remains of 17 tank furnaces for the production of raw glass, and the remains of similar furnaces have come to light at Apollonia (Arsuf).13 Evidence for secondary glassworking has also been found at a number of sites in Judaea.14

These observations lead to the following conclusions about the section on glass in Diocletian's price edict:

1. Lines 1 and 2 refer to raw glass.

2. Vitrum Alexandrinum was made in Egypt, and vitrum Iudaicum was made in Judaea.

3. Vitrum Iudaicum was naturally colored green glass.

4. Lines 3 and 4 refer to vessels without decoration.

5. Lines 5 and 6 refer to windowpanes.

6. Raw glass, plain vessels, and windowpanes were sold by weight.

This article was published in the Journal of Glass Studies, Vol. 46 (2004), 189–191.

Acknowledgments. I am grateful to Prof. Kevin Butcher and, in particular, Prof. Michael McCormick for their helpful comments on the continued use of the term "Judaea" after it ceased to be the name of a province.

1. K. T. Erim and Joyce Reynolds, "The Aphrodisias Copy of Diocletian's Edict on Maximum Prices," Journal of Roman Studies, v. 63, 1973, pp. 99–110. Pages 108–109 contain notes on the glass prices by Dorothy Charlesworth. The fragments from Aphrodisias were incorporated into an edition of the entire document, based on all known fragments, by Marta Giacchero, Edictum Diocletiani et Collegarum de pretiis rerum venalium, Pubblicazioni dell'Istituto di Storia Antica e Scienze Ausiliarie dell'Universita di Genova, v. 8, Genoa: the institute, 1974.

2. It occupies col. 3, lines 34–41 of the Aphrodisias fragments, and it represents section 16, lines 1–6 of the entire edict.

3. Charlesworth [note 1].

4. The adjective lēvis means "light" or "smooth." Juvenal (14.62), writing of silver, used it to mean "smooth" in the sense of objects that were neither chased nor engraved. Cf. Charlton D. Lewis and Charles Short, A Latin Dictionary, Oxford: Oxford University Press, impression of 1975, p. 1015, s.v. levis. In the present context, "plain," meaning "undecorated," seems to be a logical translation.

5. Dan Barag, "Recent Important Epigraphic Discoveries Related to the History of Glassmaking in the Roman Period," Annales de l'Association Internationale pour l'Histoire du Verre, v. 10, Madrid and Segovia, 1985 (Amsterdam, 1987), pp. 109–116.

6. Ian C. Freestone, Yael Gorin-Rosen, and Michael J. Hughes, "Primary Glass from Israel and the Production of Glass in Late Antiquity and the Early Islamic Period," in La Route du verre: Ateliers primaires et secondaires du second millenaire av. J.-C. au Moyen Age, ed. Marie-Dominique Nenna, Travaux de Ia Maison de l'Orient Méditerranéen, no. 33, Lyons: Maison de l'Orient Méditerranéen-Jean Pouilloux, 2000, pp. 65–83.

7. E. Marianne Stern, "Roman Glassblowing in a Cultural Context," American Journal of Archaeology, v. 103, 1999, pp. 441–484, esp. p. 465. For window glass in general, see David Whitehouse, "Window Glass between the First and the Eighth Centuries," in Il colore nel Medioevo: Arte, simbolo, tecnica, v. 3, La vetrata in Occidente dal IV all'XI secolo, ed. Francesca Dell' Acqua and Romano Silva, Lucca: Istituto Storico Lucchese, Scuola Normale Superiore di Pisa, and Corpus Vitrearum Medii Aevi Italia, 2001, pp. 31-43.

8. Caroline M. Jackson, H. E. M. Cool, and Emma C. W. Wager, "The Manufacture of Glass in Roman York," Journal of Glass Studies, v. 40, 1998, pp. 55–61.

9. Cc. ser. Lat. 175.13.

10. Contra Vigilianum 5 PL 23.358.

11. Origines [Etymologiae] 14.3.21.

12. Michael Avi-Yonah, The Madaba Mosaic Map, Jerusalem: Israel Exploration Society, 1954, p. 44.

13. Oren Tal, Ruth E. Jackson-Tal, and Ian C. Freestone, "New Evidence of the Production of Raw Glass at Late Byzantine Apollonia-Arsuf, Israel," Journal of Glass Studies, pp. 51–66 in this volume.

14. Yael Gorin-Rosen, "The Ancient Glass Industry in Israel: Summary of the Finds and New Discoveries," in La Route du verre [note 6], pp. 49–63.

Published on March 28, 2013