The Koson Stater

The origin of the fascinating Koson staters has long puzzled historians and numismatists. Erasmus of Rotterdam first commented on them in 1520. A hoard containing several thousand coins was discovered in 1543 at or near Sarmizegetusa, the ancient capital of the Dacian kingdom. Other hoards and individual coins have been found since, primarily in Transylvania (ancient Dacia, in modern Romania).

The obverse imitates a Roman denarius struck by Marcus Junius Brutus (the most famous of Caesars assassins) in 54 B.C. depicting his ancestor L. Junius Brutus (the traditional founder of the Roman Republic) in the center, accompanied by two lictors, with a monogram left and KOΣΩN in the exergue. The reverse imitates a Roman denarius struck by Pomponius Rufus in 73 B.C. depicting an eagle standing left on scepter, with wings open and raising a wreath in its right talon.

A centuries old theory proposed the type was issued by Koson, a wealthy Scythian dynast, who ruled from Olbia, c. 44 - 29 B.C. Coins issued by the Dacian Kingdom during this period imitated types of the Roman Republic and often used obverse and reverse types from different coins. The ligature on the obverse has been interpreted as OΛB, a mintmark for Olbia, or BA for the Greek title BASILES (king). The eagle was a common type for coins struck at Olbia. After the Geto-Dacian King Burebista died in 44 B.C., the Dacian Kingdom, which included Olbia, was divided into four (later five) parts. Perhaps Koson was the ruler in Olbia after this division of the Dacian Kingdom.

The type has alternatively been attributed to Caesar 's most famous assassin, Marcus Junius Brutus. The Republican obverse type from one of his own previous issues certainly supports attribution to Brutus. The ligature on the obverse does appear to be a BR monogram, which also supports attribution to Brutus. According to this theory, the gold was supplied by the Roman senate to Brutus, and Brutus struck the coins to pay a Dacian king named Koson for mercenary forces supplied for the civil war against the triumvirs, Mark Antony, Octavian and Lepidus.

Both of these theories and others have been much debated. Some numismatists, in the not too distant past, even doubted the coins were ancient.

In 2002, the first testing and analysis of the Koson stater with metallurgical methods like XRF, micro-PIXE and micro-SR-XRF confirmed that the gold used to strike these coins is ancient. Now we have further surprising and enlightening results. New investigations were conducted in 2012 by the National Institute for Physics and Nuclear Engineering in Bucharest, Romania, in the Institute for Synchrotron Radiation at Forschungszentrum Karlsruhe in Germany, and in the Laboratori Nazionali di Legnaro in Padua, Italy. A link to the the research results is provided below.

The results make it clear that we must distinguish between two different types of Koson staters: coins with monogram (type 1, see the photograph above) and coins without monogram (type 2, see the photographs below). The coins without monogram (type 2), in addition to lacking the monogram, were struck with coarser style dies and usually have rougher surfaces. The differences indicate the two types probably were not struck simultaneously by the same mint. The new research has revealed that these two groups were also made from two different gold sources. The coins with monogram (type 1) do not contain tin (Sn) or antimony (Sb), but the coins without monogram (type 2) contain significant amounts of tin and antimony.

The analysis indicates coins with monogram (type 1) were struck with gold refined by the process used by the Roman Republic. Tin (Sn) and antimony (Sb) were removed during the refining process.

The coins without monogram (type 2) were struck with natural unrefined gold, as was found in the rivers of ancient Dacia. The gold is identical to the gold of the bracelets from Sarmizegetusa, the ancient capital of the Dacian kingdom. Since the gold is unrefined gold from Dacia, and the Dacians had not mastered the Roman refining process, the analysis indicates the coins without monogram (type 2) were struck by the Dacians themselves. Nearly all coins struck by the Dacians during this period imitated coins of the Roman Republic. The coarser style and rougher surfaces also indicate the coins without monogram (type 2) were struck by the Dacians. The research and other evidence convincingly indicate the Koson staters without monogram (type 2) were struck by the Dacians, probably at Sarmizegetusa.

As discussed above, several readings of the monogram have been proposed: (1) OΛB - a mintmark for Olbia; (2) BA - abbreviating the Greek word for king, BASILES; or (3) BR - abbreviating Brutus, the famous assassin of Julius Caesar. Understanding that the type with the monogram was struck with Roman gold, and that the type without ligature was a Dacian imitative, seems to strongly support reading the ligature as BR, for Brutus. First, we should note, were it not for the reverse inscription "KOSN" it seems likely that no one would have interpreted this ligature as anything but BR. The ligature is often obscure, but on coins where it seems most clear, at a glance, the letters B and R are the most obvious interpretation. It is very difficult to see how it can be read as OΛB. BA only makes sense if it refers to King Koson. But why would the Dacians remove the title on imitatives if it was the title of their king. If the monogram actually is BR and stands for Brutus then it is understandable that, after the defeat at Philippi and the death of Brutus, the Dacians removed his name from their coins. The gold is Roman gold, the types strongly support attribution to Brutus, and the most likely monogram is BR. The research and other evidence strongly indicate the Koson staters with monogram (type 1) were struck by Brutus. That they have been found primarily in Transylvania and often in large hoards strongly indicates Brutus struck them to pay a Dacian ruler or rulers to provide mercenary forces.

There is still the question of the meaning of the inscription, "KOΣΩN." Although many names of other Dacian and Scythian kings are known, the name Koson is otherwise unknown. There are, however, many ancient kings almost entirely lost from history, and who are today only remembered by their coins. It has also been suggested that KOΣΩN may be a misspelling of Cotiso (or Cotison) a king mentioned by Horace and Suetonius. A link to the Wikipedia page on Cotiso is provided below.2 

Perhaps KOΣΩN is not the name of a king at all. Robert Kokotailo has proposed that KOSN could be a flawed Greek transcription of COS with a plural genitive suffix. BR KOΣΩN could have been intended to mean, "(of) the Consul Brutus." Although technically incorrect, many Dacian inscriptions have similar grammatical errors, especially in Latin texts translated to Greek. Although odd and unique, KOΣΩN may have been the best possible transcription in the Dacian dialect. A link to Robert Kokotailo 's article "Koson Gold Stater" is provided below.3 


                      
            Koson stater without monogram (Type 2).                                                                                                     
            Photograph courtesy of Ancient Numismatic Enterprise. Photograph used with permission. 

A significant problem with this theory is that Marcus Junius Brutus was never made consul by the senate. However he did adopt the title of Pro Consul during his rebellion against the forces of Octavian in 43 to 42 BC, with or without official sanction, using it on his coins to pay his own troops, as can be seen on this example, and other types exist (from Calgary Coin) 

          Image from CNG Coins


References:

(1) Proceedings of the Romanian Academy, Series A, Volume 13, Number 1/2012, pp. 19-26. http://www.acad.ro/sectii2002/proceedings/doc2012-1/03-Constantinescu.pdf.

(2) Wikipedia. "Cotiso." http://en.wikipedia.org/wiki/Cotiso

(3) Kokotailo, R. "Koson Gold Stater."  http://www.calgarycoin.com/reference/articles/koson/koson.htm.