Late Antique and Byzantine Weights in the Mediterranean Area

This project aims at a comprehensive publication showing the origin, development and use of late antique and Byzantine weights from the 4th to the10th century AD in the Mediterranean area. Based on a detailed catalogue, a typology of the weights will be developed and fitted into a linked chronological framework. Weights are essential tools of a regulated trade and coin circulation. They can identify the domestic and long- distance trade relations of the late antique and Byzantine Empire. The inscriptions and monograms of officials on the weights are an important prosopographic source that gives us insights into the administrative structure. Based on their distribution, the size of the sphere of influence of the individual hierarchical levels can be determined. It will be of significant importance to point out those decisions based on historical events that have led to the introduction of new weight types. Finally, the influence of the Byzantine system of weights on the regions outside the borders of the empire will be illuminated.

In archaeology and numismatics, late antique and Byzantine weights represent a research desideratum, and even numismatists consider them "paranumismatic". It is not surprising that up to now no comprehensive publication but only general summaries exist on the subject.Weights for weighing goods and coins are an important control mechanism of a functioning state. They guarantee correct tax revenue and a transparent control on the part of the citizens. Now and then, the aim was to create trust in the government authority and the market. Without such a system, regulated tax payments, the exchange of goods and a controlled circulation of money would not work properly. The legislative texts of the Codex Theodosianus and their amendments under Justinian I emphatically show that great importance was attached to certified weights and their proper storage.Late antique and Byzantine weights were produced in various forms and made of different materials such as copper alloys, lead, silver, stone or glass. They are mainly marked by Greek face value stamps that indicate their target weight. The design of the surface can differ from simple engravings to complex figurative and architectural pictures inlaid with various metals.The size of the late antique / Byzantine Empire was a huge logistical challenge in terms of introducing and maintaining a uniform system of weights throughout the whole territory of the state. Today, weights and scales seem natural, but an international system of units ("International System of Units" abbreviated SI) was first introduced in 1960 and established over the following decades.Most of the weights were used weighing money and especially gold coins. The three main gold nominals were the solidus of about 4,5 g and its two fractions, the semissis (about 2,25 g) and the tremissis (about 1,5 g). The solidus consisted of 24 carats (24 ???????). The gold coins were used primarily by the state to pay the wages for their servants like the soldiers or officials. In the other direction, the state collected taxes from its citizens, mainly to be paid in gold coins. To guarantee the solvency of the Byzantine state it had to raise more money than it spent. It was estimated that in the 6th century AD the tax revenue was about 4.8 million solidi per year from the state prefectures, three quarters of it coming from the prefecture of Oriens alone. Moreover, tax incomes were collected from financial and domain administrations. For all these financial transactions money had to be weighed and controlled by state officials.From the metrological point of view it is evident that at least the glass weights were amazingly accurately calibrated.