Search Results (18)

A series of 11 Byzantine gold coins were investigated, including two examples of an extremely rare type called histamenon “stellatus”, from around the reign of the Byzantine emperor Constantine IX Monomachos (AD 1042–1055). The methods applied were X-ray fluorescence spectroscopy (XRF), specific density measurement (SD), and scanning electron microscopy (SEM). The debasement (decreasing gold content) of the Byzantine nomisma gold coinage during the 11th century was demonstrated. A method combining XRF and SD measurement combined with a graphical presentation/analysis called a ternary plot was also demonstrated. The measured gold content of the 11 coins was corrected for the possible “outwashing” effect and a potential cleaning of ancient gold. A model for the estimation of the gold content of Byzantine histamenon nomisma gold coins from the period AD 1020–1118, based on the specific density (SD), was derived. It was demonstrated that two analyzed histamenon “stellati” coins likely were minted around AD 1054–1055, possibly during the same period as the occurrence of the supernova SN1054, known as the Crab-nebula. It is further discussed if the gold content and size of the stars shown on those coins can be correlated to the visibility of the supernova from June AD 1054 to January AD 1055. Full article

Geographic Information Systems and the use of thematic maps have become well-established tools in archaeology. However, not all the sectors of archaeology still take advantage of these technologies. One such sector is numismatics, where there are still relatively few works on the implementation of coin spatial databases and the related maps. This can be verified both in academic journals indexed in major scientific databases (such as Scopus, ScienceDirect, and Web of Science) and in broader platforms like Google Scholar. In this paper, in an attempt to begin filling the gap, the methodology and results of the creation of the GIS and the Atlas of Antoniniani in Sicily are presented. The second half of the third century ASD is an interesting period because of the socioeconomic crisis that characterized it. The Atlas serves as a useful tool for providing a fresh new insight into the economy and coin circulation during this time. Full article

Non-destructive, specular laser reflectometry, an industrially used and easily accessible method, is adapted in numismatic research to the inspection of coins of the Gallic Roman Empire with the objective of the allocation of mints and/or the identification of different minting techniques. For this purpose, the laser-reflectometric fingerprints of three series of coins each consisting of five antoniniani (or radiates) of the Gallic Roman Empire originating from two mints—Trier and Cologne—are systematically determined, analyzed and correlated with the corresponding XRF element analysis. The results show that the use of an inexpensive red-emitting laser system (wavelength 632.8 nm) with a beam diameter $d<0.5$ mm and a sample mount that can be adapted to the individual shape and thickness of the coins leads to signal intensities that can be systematically recorded over a large angular range with a very good signal-to-noise ratio (SNR $>10$). While the signals cannot be used to assign individual coins to mints, we discuss the possibility of a statistical analysis. Although each coin set consists of only five samples and thus requires further study, the results here suggest that the sets can be distinguished from each other, that there is a correlation to the silver concentration and that it is possible to estimate the refractive index n. Full article

The numismatic collection in the Auckland War Memorial Museum Tāmaki Paenga Hira, Auckland, New Zealand, is an extensive although little-known collection. As part of a wider rehousing project for the coins, a trial was conducted to rehouse the Greek and Roman coins to establish the best storage and analysis practices. Records were also created or updated during this process to make them visible online and enable their use in future research. Best practice standards include handling and measurement practice, retaining all existing information about the collection, and, where possible, reuniting coins with their acquisition information. The project’s end goal is to create populated records in the museum database (Vernon) for the entire numismatic collection, either through updating existing records, creating records using available acquisition information, or creating records with temporary numbers where that information has been lost. This report gives a brief history of the collection and the rehousing process and suggests future research avenues. Full article

We report here the results of a multi-analytical approach to characterize twelve Roman coins dating from the third century B.C. to fifth century A.D. that were found in the surroundings of Rome and for which the year of minting is determined by numismatic analysis. The coins were studied using SEM-EDS, EMPA, XRD, and FTIR techniques, enabling semi-quantitative and quantitative determinations of the chemical and mineralogical composition of the alloys and corrosion products. SEM-EDS analyses highlighted the occurrence of corrosion products on the surfaces and wide chemical variations due to selective enrichment or depletions of the alloying metals. The EMP analyses showed that three of the twelve coins are made of copper (1), one is a copper–tin alloy (2), five are copper–tin–lead alloys with elements in different proportions (3), two are copper–lead alloys (4), and another one is a subaerata coin (5). In addition, the physical parameters of the coins, i.e., density, weight, and diameters, were measured to have an overall characterization. Full article

A sample of 18 double-relief coins from different poleis of Magna Graecia and ancient Italy has been analysed using a handheld XRF spectrometer directly inside the Museo Provinciale Campano (Capua, Italy). The data analysis shows that (i) the main elements are Ag and Cu, indicating that the coins are of high fineness (average Ag 95.7%), (ii) trace elements can help to characterise the coins, (iii) a superficial chemically altered layer (corrosion) is absent, (iv) the values of ratio Ag Kα/Lα evidence the presence of an enrichment layer on the surface of silver or subaerata in some coins. Multivariate statistical analysis and graph analysis allowed the coins to be assigned to different groups with the highest possible accuracy on the basis of the chemical data obtained and models to be constructed to classify the coins according to their historical periods. Full article

Ancient numismatics, the study of ancient coins, has in recent years become an attractive domain for the application of computer vision and machine learning. Though rich in research problems, the predominant focus in this area to date has been on the task of attributing a coin from an image, that is of identifying its issue. This may be considered the cardinal problem in the field and it continues to challenge automatic methods. In the present paper, we address a number of limitations of previous work. Firstly, the existing methods approach the problem as a classification task. As such, they are unable to deal with classes with no or few exemplars (which would be most, given over 50,000 issues of Roman Imperial coins alone), and require retraining when exemplars of a new class become available. Hence, rather than seeking to learn a representation that distinguishes a particular class from all the others, herein we seek a representation that is overall best at distinguishing classes from one another, thus relinquishing the demand for exemplars of any specific class. This leads to our adoption of the paradigm of pairwise coin matching by issue, rather than the usual classification paradigm, and the specific solution we propose in the form of a Siamese neural network. Furthermore, while adopting deep learning, motivated by its successes in the field and its unchallenged superiority over classical computer vision approaches, we also seek to leverage the advantages that transformers have over the previously employed convolutional neural networks, and in particular their non-local attention mechanisms, which ought to be particularly useful in ancient coin analysis by associating semantically but not visually related distal elements of a coin’s design. Evaluated on a large data corpus of 14,820 images and 7605 issues, using transfer learning and only a small training set of 542 images of 24 issues, our Double Siamese ViT model is shown to surpass the state of the art by a large margin, achieving an overall accuracy of 81%. Moreover, our further investigation of the results shows that the majority of the method’s errors are unrelated to the intrinsic aspects of the algorithm itself, but are rather a consequence of unclean data, which is a problem that can be easily addressed in practice by simple pre-processing and quality checking. Full article

This study aims to explore the connection between religious and military spheres in Constantinian propaganda. The extensive use of propaganda and the notorious public discourse which involves the dynamics of power during Late Antiquity show how religion and the military played a key role. This principle reaches a singular meaning in the case of emperor Constantine I. To this extent, this paper considers several kinds of sources, which include legal, literary, and numismatic, among others. An analysis of the political uses of imperial constitutions by the emperor (especially CTh 7.20.2) can be of particular interest in order to address the ideas of self-representation and the politics of legitimation. Ultimately, the paper highlights the importance of imperial propaganda in Later Roman society, as well as the transformations in Constantine’s public discourse, where the connection between army and religion shows an evolution from the previous ways of understanding imperial power and where the bond of the ruler with a supreme divinity is a central issue. Full article

This study stems from the need for numismatics to establish whether there may be relationships between a group of 103 bronze coins from the Roman era found in archaeological excavations on the Cesén Mountain (Treviso, Italy) and a group of 117 coins kept at the Museum of Natural History and Archaeology in Montebelluna (Treviso, Italy). The chemists were delivered six coins with neither pre-agreements nor further information on the origin of the coins. Therefore, the request was to hypothetically assign the coins to the two groups on the basis of similarities and differences in their surface composition. Only non-destructive analytical techniques were allowed to be used to characterize the surface of the six coins taken blindly from the two sets. The elemental analysis of each coins’ surface was carried out by µ-XRF. To better observe the morphology of the coins’ surfaces, SEM-EDS was used. Compounds covering the coins coming from both corrosion processes (patinas) and the deposition of soil encrustations were also analyzed by means of the FTIR-ATR technique. The molecular analysis confirmed the presence of silico-aluminate minerals on some coins, unequivocally indicating a provenance from clayey soil. Some soil samples, collected from the archaeological site of interest, were analyzed to verify whether the encrusted layer on coins could contain chemical components compatible with them. This result, together with the chemical and morphological investigations, led us to subdivide the six target coins into two groups. The first group is made up of two coins coming from the set of coins from excavation (found in the subsoil) and from the set from open air finds (coins found in the top layer of the soil). The second group is made up of four coins that are devoid of characteristics corresponding to exposure to soil contact for long periods of time and, moreover, their surface compounds could suggest a different provenance. The analytical results of this study made it possible to correctly assign all six coins to the two groups of finds and support numismatics, which was unconvinced in considering all coins to come from the same finding site only on the basis of archaeological documentations. Full article

This article explores the surprisingly positive attitude towards pilgrimage and saints that developed within mainstream Lutheran faith during the Seventeenth Century. To acknowledge this strand in the theology of the 1600s in some ways runs contrary to what is often stated about the period, the heyday of Lutheran Orthodoxy, and to a certain extent incompatible with what is generally perceived as ‘Lutheran’. I aim to show the 1600s as a period with a great curiosity towards the development of new devotional practice, and a time when the search for devotional tools which could help the individual to come closer to Christ led theologians to explore texts and ideas that at least superficially could be seen as belonging to the Catholic side of the confessional divide. Full article

This article explores the Counter-Reformation medievalization of Polish–Lithuanian St. Kazimierz Jagiellończyk (1458–1484)—whose canonization was only finalized in the seventeenth century—as a case study, taking up questions of the reception of cults of medieval saints in post-medieval societies, or in this case, the retroactive refashioning into a venerable medieval saint. The article investigates these questions across a transcultural Italo–Baltic context through the activities of principal agents of the saint’s re-fashioning as a venerable saint during the late seventeenth century: the Pacowie from the Grand Duchy of Lithuania and the Medici from the Grand Duchy of Tuscany, during a watershed period of Tuscan–Lithuanian bidirectional interest. During this period, the two dynasties were entangled not only by means of the shared division of Jagiellończyk’s bodily remains through translatio—the ritual relocation of relics of saints and holy persons—but also self-representational strategies that furthered their religio-political agendas and retroactively constructed their houses’ venerable medieval roots back through antiquity. Drawing on distinct genres of textual, visual, and material sources, the article analyzes the Tuscan–Lithuanian refashioning of Kazimierz against a series of precious reliquaries made to translate holy remains between Vilnius to Florence to offer a contribution to the entangled histories of sanctity, art and material culture, and conceptual geography within the transtemporal and transcultural neocolonial context interconnecting the Middle Ages, Age of Reformations, and the Counter-Reformation between Italy and Baltic Europe. Full article

Silphion was an ancient medicinal gum-resin; most likely obtained from a Ferula species growing in the Cyrene region of Libya ca. 2500 years ago. Due to its therapeutic properties and culinary value, silphion became the main economic commodity of the Cyrene region. It is generally believed that the source of silphion became extinct in the first century AD. However, there are a few references in the literature about the cultivated silphion plant and its existence up to the fifth century. Recently, a rare and endemic Ferula species that produces a pleasant-smelling gum-resin was found in three locations near formerly Greek villages in Anatolia. Morphologic features of this species closely resemble silphion, as it appears in the numismatic figures of antique Cyrenaic coins, and conform to descriptions by ancient authors. Initial chemical and pharmacological investigations of this species have confirmed the medicinal and spice-like quality of its gum-resin supporting a connection with the long-lost silphion. A preliminary conservation study has been initiated at the growth site of this rare endemic Ferula species. The results of this study and their implications on the regional extinction event, and future development of this species will be discussed. Full article

Automatic ancient Roman coin analysis only recently emerged as a topic of computer science research. Nevertheless, owing to its ever-increasing popularity, the field is already reaching a certain degree of maturity, as witnessed by a substantial publication output in the last decade. At the same time, it is becoming evident that research progress is being limited by a somewhat veering direction of effort and the lack of a coherent framework which facilitates the acquisition and dissemination of robust, repeatable, and rigorous evidence. Thus, in the present article, we seek to address several associated challenges. To start with, (i) we provide a first overview and discussion of different challenges in the field, some of which have been scarcely investigated to date, and others which have hitherto been unrecognized and unaddressed. Secondly, (ii) we introduce the first data set, carefully curated and collected for the purpose of facilitating methodological evaluation of algorithms and, specifically, the effects of coin preservation grades on the performance of automatic methods. Indeed, until now, only one published work at all recognized the need for this kind of analysis, which, to any numismatist, would be a trivially obvious fact. We also discuss a wide range of considerations which had to be taken into account in collecting this corpus, explain our decisions, and describe its content in detail. Briefly, the data set comprises 100 different coin issues, all with multiple examples in Fine, Very Fine, and Extremely Fine conditions, giving a total of over 650 different specimens. These correspond to 44 issuing authorities and span the time period of approximately 300 years (from 27 BC until 244 AD). In summary, the present article should be an invaluable resource to researchers in the field, and we encourage the community to adopt the collected corpus, freely available for research purposes, as a standard evaluation benchmark. Full article

We propose an image-based class retrieval system for ancient Roman Republican coins that can be instrumental in various archaeological applications such as museums, Numismatics study, and even online auctions websites. For such applications, the aim is not only classification of a given coin, but also the retrieval of its information from standard reference book. Such classification and information retrieval is performed by our proposed system via a user friendly graphical user interface (GUI). The query coin image gets matched with exemplar images of each coin class stored in the database. The retrieved coin classes are then displayed in the GUI along with their descriptions from a reference book. However, it is highly impractical to match a query image with each of the class exemplar images as there are 10 exemplar images for each of the 60 coin classes. Similarly, displaying all the retrieved coin classes and their respective information in the GUI will cause user inconvenience. Consequently, to avoid such brute-force matching, we incrementally vary the number of matches per class to find the least matches attaining the maximum classification accuracy. In a similar manner, we also extend the search space for coin class to find the minimal number of retrieved classes that achieve maximum classification accuracy. On the current dataset, our system successfully attains a classification accuracy of 99% for five matches per class such that the top ten retrieved classes are considered. As a result, the computational complexity is reduced by matching the query image with only half of the exemplar images per class. In addition, displaying the top 10 retrieved classes is far more convenient than displaying all 60 classes. Full article

Ancient numismatics, that is, the study of ancient currencies (predominantly coins), is an interesting domain for the application of computer vision and machine learning, and has been receiving an increasing amount of attention in recent years. Notwithstanding the number of articles published on the topic, the variety of different methodological approaches described, and the mounting realisation that the relevant problems in the field are most challenging indeed, all research to date has entirely ignored one specific, readily accessible modality: colour. Invariably, colour is discarded and images of coins treated as being greyscale. The present article is the first one to question this decision (and indeed, it is a decision). We discuss the reasons behind the said choice, present a case why it ought to be reexamined, and in turn investigate the issue for the first time in the published literature. Specifically, we propose two new colour-based representations specifically designed with the aim of being applied to ancient coin analysis, and argue why it is sensible to employ them in the first stages of the classification process as a means of drastically reducing the initially enormous number of classes involved in type matching ancient coins (tens of thousands, just for Ancient Roman Imperial coins). Furthermore, we introduce a new data set collected with the specific aim of denomination-based categorisation of ancient coins, where we hypothesised colour could be of potential use, and evaluate the proposed representations. Lastly, we report surprisingly successful performances which goes further than confirming our hypothesis—rather, they convincingly demonstrate a much higher relevant information content carried by colour than even we expected. Thus we trust that our findings will be noted by others in the field and that more attention and further research will be devoted to the use of colour in automatic ancient coin analysis. Full article