NGC Ancients: An Earlier Date for the Gold Tetarteron Nomisma?

During the thousand-year history of the Byzantine Empire, a great variety of coins were issued in gold and debased gold. One of the more interesting was the tetarteron nomisma, which was produced for a little more than a century and which to this day remains a bit of a mystery.

When the tetarteron was created in the mid-10^th Century A.D., the standard Byzantine gold coin was the solidus, which had been the benchmark coin for international commerce in the Mediterranean world for more than six centuries.

A gold solidus of the second reign of Emperor Justinian II (A.D. 705-711).

The introduction of the tetarteron nomisma, which circulated alongside the solidus, compelled modern scholars to give the solidus a new name, even though its size, fabric, weight and purity were identical to the venerable solidus. The reason for “renaming” the solidus the histamenon nomisma is one of semantics.

Byzantine coin scholar Philip Grierson, principal author of the standard catalog of Byzantine coinage (based upon the Dumbarton Oaks Collection), notes that solidus is a Latin term, and that the existence of two gold coins prompted the name solidus to be abandoned in favor of the Greek term nomisma, with the heavier version (the old solidus) being called a histamenon and the lighter one a tetarteron.

Naming aside, the tetarterion must have injected a great deal of confusion into the Byzantine monetary system, for aside from its lighter weight (about 8% lighter than the solidus/histamenon), nothing about its design, style or fabric differed from the solidus/histamenon to provide a visual cue that the coin was any different.

Making matters worse, it was not uncommon in the Byzantine world for gold coins to have their edges shaved, filed or clipped to remove weight. Unsavory characters would do this, keep the extra gold, and then try to pass the coin back into circulation at full value. This had been a problem in the Roman and Byzantine world for at least as long as the solidus (with its thin edge) had been in production.

These later gold tetartera of and Theodora (A.D. 1055-1056) and Romanus IV (1068-1071) bear distinctive designs and have planchets with irregular edges characteristic of later tetartera.

Fortunately, with the passage of time meaningful differences in the design and fabric of the tetarteron made it possible to easily distinguish it from the heavier histamenon. The tetarteron ceased to be struck in A.D. 1092 – a casualty of a coinage reform of the emperor Alexius I (A.D. 1081-1118). Thereafter the name tetarteron was used for a small copper coin of very low value.

Manuel I (A.D. 1143-1180) issued these copper tetartera after the reform of A.D. 1092.

This copper weight for gold tetartera dates to the 10th to the 12th Centuries A.D.

Much has been written about why the tetarteron was introduced. The topic is summarized well by Grierson:

“Byzantine tradition regarded its introduction as a measure of official debasement: Nicephorus’ greed, or at least his need for money, gave him the idea of settling government obligations in the lighter coin while requiring taxes and other dues to be paid in those of full weight. Other explanations are possible, for it was not the first time that light-weight [Byzantine gold coins] had been issued.”

The emperor to whom Grierson refers is Nicephorus II (A.D. 963-969), who by literary tradition of Medieval Byzantine chroniclers, is credited with the introduction of the tetarteron, seemingly in about A.D. 963. This presumed date of introduction is broadly accepted in the academic and collector communities.

The William Oldknow example: presumably a tetarteron of Romanus II.

However, a coin from the collection of William Oldknow recently examined by NGC Ancients may challenge the literary record and the presumption that the tetarteron was introduced by Nicephorus II. Rather, it may have been introduced a few years earlier, during the sole-reign of Nicephorus II’s predecessor, Romanus II (A.D. 959-963).

This intriguing gold coin is being offered in the auction of Ira and Larry Goldberg in their session of New York Sale on January 12, 2021.

At 4.12 grams, this gold coin of Romanus II has what would be an uncharacteristically low weight for a solidus/histamenon, which would be expected to weigh about 4.40 grams or more. The usual explanation would be that metal was removed from the edge by clipping or filing, thus reducing the weight of the coin. As noted earlier, this was an age-old practice in the Byzantine world.

However, that is not the case with this specimen. The edge has a few minor edge marks typical of circulation, yet all are small enough that they did not remove any consequential amount of metal. So, the significantly low weight of this coin is noteworthy.

Other similarly low-weight gold coins of Romanus II are recorded, though without our being able to examine those coins it is impossible to know whether their low weights are the result of a low production weight (as here) or post-production clipping.

The precise dating of this coin is of some interest since it impacts the likelihood of it representing the earliest issue of tetartera.

Its obverse shows the facing bust of Christ, and its reverse shows the facing half-busts of the emperors Constantine VII and his son (and heir) Romanus II, who hold between them a patriarchal cross.

This familiar type was first struck in A.D. 946 and was continued through A.D. 963. For most of that period (until A.D. 959), Constantine VII was alive and reigning, and thereafter the type was continued by his son Romanus II. This coin belongs to the final four years of issuance – A.D. 959 to 963 – when Romanus II reigned alone (yet still used his father’s coin design).

This is made clear in the groundbreaking research of the late Franz Füeg as presented in his Corpus of the Nomismata from Anastasius II to John I in Constantinople 713-976. He provides compelling research to distinguish the dates of this long series of gold coins. This coin fits into the final grouping, for which the key diagnostic is the obfuscated inscription on the reverse (which on earlier issues of this type bore the names of the two emperors).

Füeg says of the reverse inscription: “The majority of the letters have been replaced by more or less letter-shaped ciphers in the same number necessary for a correct inscription” and he makes clear that, “These were not issued under Constantine VII, but during the government of Romanus II.”

Thus, we can place this intriguing gold coin, with the unexpected weight of the tetarteron, to A.D. 959 to 963 – a four-year period just prior to the reign of Nicephorus II, the emperor who is traditionally credited with the introduction of the tetarteron.

It is precisely coins like this which remind us of countless instances in history and numismatics where the accuracy of the literary record is questioned – and often overturned – by observation based upon surviving artifacts.

Whether this will be considered valuable information by the scholarly community remains to be seen, but it is worth sharing in the event useful conclusions can be derived.

NGC would like to thank Cécile Morrison, Director of Research emeritus at the French National Center for Scientific Research, for generously sharing her expertise and for providing research materials used in the preparation of this article.

Images courtesy of Classical Numismatic Group, LLC and NGC.

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