Vol. VI of the Sylloge Nummorum Parthicorum aims to reconstruct in full the structure of the coins series struck by the Arsacid kings between c. AD 8 to 51. Covering the reigns of Vonones I, Artabanus II, Vardanes, Gotarzes II, and Vonones II, it is marked mainly by the long reign of Artabanus II, c. AD 10-38, and the struggle following his demise between his two successors Vardanes and Gotarzes II in the years AD 40-46. After consolidating his power, in AD 49 Gotarzes had to face Meherdates, the last Arsacid challenger to the throne sent by Rome. In AD 51 Gotarzes was followed briefly by Vonones II, and by the autumn of the same year Vologases I had ascended to the throne to begin a reign that lasted twenty-eight years.
All the coins gathered for Vol. VI have been digitally registered together with their specific technical data. A total of 1,846 specimens from the collections officially involved in the SNP project will be individually catalogued and illustrated. A further 1,124 specimens from other collections and auction houses have been added to enlarge the documentary basis. All this material has been examined to produce an initial typological classification followed by a full reconstruction of the connections between the types and series, i.e. the entire structure of production. Whereas for this period Sellwood 1980 listed 193 varieties divided in eight main issues without any attempt at a detailed classification, for SNP VI 21 obverse and 57 reverse types have been reconstructed, all illustrated by drawings. Complemented by all other available sources, This phase of the project provided the basis for the historical reconstruction and interpretation.
Among the main results of this project has been the new picture of mint activity that has emerged, especially in conjunction with the work conducted on SNP VII. In fact, drachm production appears to have been carried on well into the second half of the 1st century AD in more mints than what previously supposed, as shown by the cases of Rhagae and Mithradatkart. Moreover, the reappraisal of the sequence of the coin issues has produced a much firmer context for the historical reconstruction. Contrary to previous hypotheses, tetradrachms of Vardanes and Gotarzes II do not overlap in the years AD 44-46, and Gotarzes began his issues only in June AD 46, continuing up to AD 51. This has even helped to clarify the drachm sequence. It has been commonly assumed the series of Gotarzes were followed by the peculiar drachms with king in a tiara ascribed to Vonones II, and then by those attributed to Vardanes II, who was also striking tetradrachms in Seleucia in the context of his rebellion against Vologases I in AD 55-58. However, the thorough study of typology and style of the drachms has led to the conclusion that it is not possible to separate the drachms of the alleged Vardanes II from those of Vardanes I, requiring the whole sequence to be moved to an earlier chronology. On the basis of the peculiar typology, the series with king in a tiara should therefore be ascribed to Vardanes as his final issue before Gotarzes began to strike his series.
To sum up, the combined study of drachms and tetradrachms shows that Artabanus was succeeded by Vardanes, who initially succesfully prevailed against Gotarzes, only to be eliminated in AD 46. Gotarzes ruled in full control from summer AD 46 to spring AD 51, leaving the throne to Vonones II, whose rule lasted only for a few months without striking any coin at all.