Mithraic studies remain a viable field of study due to both the continuous emergence of specialized publications that review the theoretical framework of knowledge concerning Mithraism, and the incorporation of discoveries, especially from archaeology, that provide new elements of study and knowledge in all regions of the Roman Empire. Due to the dispersion of these discoveries and the large number of publications, the progress of knowledge continues to be sustained by the same evidences, which is present in the general catalogues that are available. In the case of Mithraism, the first general catalogue was prepared by Franz Cumont in 1896, and revised and expanded by Martin J. Vermaseren between 1956 and 1960. These books established the foundation for reference works that have systematically collected all the archaeological, iconographic and epigraphic evidence for the cult of Mithras throughout all Roman provinces. In subsequent years, other catalogues have focused on more specific regions, analysing and interpreting the presence of the cult of Mithras in these regions.
The case of the Iberian Peninsula is an important example of how discoveries have been contributing to our understanding of Mithraism. The shortage of documents at the end of the nineteenth century led Cumont to point out that “On n’a découvert en Espagne aucun monument mithriaque authentique, du moins á ma connaissance”. Vermaseren was able to correct his teacher’s statement, and in his catalogue, he identified up to 41 documented items, but it was not until 1967 that Garcia y Bellido identified not only Mithraism, but the other eastern religions present on the Peninsula. These foundational publications supported the other catalogues published from the eighties to the present day.
It should be noted that Alvar is offering us here a revision of his first work published in 1981 with the same title.Scholars do not often return to a work from the beginning of their career and undertake a significant revision, updating most of the data for the theoretical framework and the conclusions from that time, but this case is a clear reflection of the progress in the field that has occurred in the last forty-five years. There are more than twice the number of pieces collected in this new work than those identified in 1981. The interest in Mithraism was such that in the same decade, two catalogues with the same title were published (Francisco Muñoz, 1989 and María Antonia de Francisco, 1989). Rightly, Alvar undertakes an exhaustive review of these, highlighting their weaknesses and the reasons why both works are of little relevance in historiography. Alvar is particularly critical of another recent investigation (Claudina Romero, 2016) that claims to update the catalogue on Iberian Mithraism but is mainly focussed on iconography, highlighting the lack of depth of many of her identifications and conclusions. The need for this recent catalogue is thus justified by several factors: not only because Alvar is the most renowned Spanish specialist in Mithraism, with deep global and local knowledge of the subject that supports his point of view, revision, and interpretation of the Mithraic evidence, but also because the number of discoveries which have appeared in recent years in relation to the presence of the cult of Mithras in the Iberian Peninsula have made any previous publication on the topic obsolete. Finally, the absence of a synthetic work like this has meant, as the author points out (p. 71), that scholarship has reflected only a partial knowledge about the presence of Mithras in Hispania, a limitation which was still reflected in the general works concerning Mithraism.
The historical study with which the author starts this catalogue (pp. 21–58) is preceded by a large map by José Carlos López Gómez, which updates the distribution of Mithraic materials in the Iberian Peninsula, and a presentation of the work by Professor Antonio Gonzales. This first chapter is set up in three parts, which set out the most recent views on the processes of the diffusion, development, and disappearance of the Mithraic cult in Hispania. It is relevant to note how the recent excavations in Mérida have forced a revision not only of the dating of the appearance of Mithras on the peninsula, but also of the thinking behind the routes that it had taken. The date that arises for the mithraeum at Mérida of around the last quarter of the first century A.D. places it among the earliest evidence for Mithraism anywhere in the empire. In addition, as the author points out, the location of Mérida discounts the diffusion models concerning the inland coast, which until then had predominated for the Hispanic case. In the opinion of Alvar, Mithraism in Hispania is defined by the role played by the senior officials of the provincial administration (as seen in Lugo or Tarraco), with certain local variants that must be highlighted, and characterized by very uneven and unbalanced territorial diffusion. This same regionalization also defines the disappearance of Mithraism in Hispania. The end comes about as a result of the progressive abandonment of the not very numerous local communities, rather than as a result of the alleged direct action of Christian persecution, which, in Alvar’s eyes, was not responsible for the end of the Mithraic cult (p. 53).
The Catalogue begins with a presentation (61–71) that not only justifies the need for it, but also reviews the deficiencies of earlier work. The catalogue of materials (pp. 73–191) is divided into three chapters that correspond to the Roman provinces of the Iberian Peninsula: Lusitania (pp. 73–129), Baetica (pp. 131–145), and Tarraconensis (pp. 147–191).
At first glance, the huge imbalance between the volume of items found in the different provinces is surprising. Lusitania offers the most, with 42 pieces. The increase in Mithraic evidence from this province is significant if we compare it with the 16 Alvar referred to in 1981. In this province, 2 mithraea and 40 objects have been identified, including inscriptions (10), sculptures, (22), altars (2), lamps (2) and various other pieces (5). The largest amount of evidence comes from the city of Mérida and the excavation of the mithraeum in Espronceda Street. No new items have been found in the other settlements.
The Baetica province has not contributed any relevant modification in terms of Mithraic evidence: 8 pieces (1 possible Mithraeum, 3 inscriptions and 4 sculptures). Although their provenances are more geographically diffuse, Alvar only introduces one new item in section, which concerns the still unconfirmed interpretation that there could be a mithraeum within one of the rooms of a villa located in Fuente Álamo (Córdoba, Andalusia). The lack of solid documentation on this issue and the author’s own reservations (p. 145) should have led him to exclude this site from the catalogue. Its inclusion could cause confusion by giving validity to an element whose Mithraic ascription is still doubtful.
The Tarraconensis province equals the province of Lusitana in terms of number of pieces and it exceeds it in places of worship (3). Inscriptions abound (14), in comparison with sculptures (2) and a variety of undetermined materials (11). The geographical dispersion of this evidence is also relevant to the Lusitanian case. They are concentrated in the area of Catalonia and then on the Atlantic side. The epigraphic identification within the inscriptions (p. 153, 162) of a local variant using “K” as a symbol to refer to Cautes is relevant. This area has produced a substantial number of new archaeological items compared to previous catalogues. The excavations of the mithraea of the Roman villa of Els Munt (Tarragona, Catalonia) and the city of Lugo (Galicia) have contributed interesting material and forced a rethinking of the presence of Mithraism in Hispania. This does not exclude the need to review the Mithraic identification that Alvar continues to grant to highly doubtful materials from Iluro (Mataró, Barcelona), which he indicates as pre-Mithraic (pp. 157–162).
The final appendix (“Fuera de Catálogo”, pp. 195–230) includes those pieces that cannot continue to be considered part of the Mithraic cult in Hispania. However, throughout the catalogue, the author has applied flexible criteria that have even led him to retain pieces whose identification raises serious doubts. The clarity and deep reasoning shown by excluding certain pieces, such as the supposed relief of the Mithraic banquet of Mérida, the plates with engraved feet from Italica, or the supposed Mithraic dedication attributed to the Elephant Tomb at Carmona, are in line with what is expected to be in a catalogue. However, the inclusion in the catalogue of some supposed Mithraea such as those at Fuente Álamo (Córdoba) or Can Modolell (Barcelona), as well as the Mithraic identification of inscriptions and pieces that Alvar himself argues are very doubtful, does not seem equally justified.
The work ends with several appendices: the abbreviations used (“Siglas y Abreviaturas”, pp. 233–235), an abundant bibliography (“Bibliografía”, pp. 237–271), and a list of images (“Lista de Ilustraciones”, pp. 273–277).
The objective proposed by the author has for the most part been accomplished, as this book offers the most useful and complete catalogue that has been published so far on Mithraism in Spain. Not only does it incorporate the latest pieces of evidence that have been discovered, but it also reinterprets the historical context and the specific characteristics that the cult of Mithras may have presented in this territory. However, there remain some questions that are not satisfactorily answered. The early dating accepted for the first mithraeum of Mérida (end of the 1st century A.D.) should compel a more elaborate explanation than Alvar provides here. Something similar happens with his proposal of how many mithraea may exist in the Peninsula. Since some are more than doubtful in the catalogue, the idea that there are 4 excavated and 14 hypothetical mithraea seems somewhat overstated. Similarly, the erroneous location (Belgian) of the Verulamium amulet (p. 207, no. 5) must be corrected. The piece is in England.
It is important that this catalogue be taken into account not only by those who wish to investigate Mithraism in Hispania and in the general context of the empire, but also by those responsible for museums that have in their displays some of the pieces which Alvar has not being Mithraic, and by those archaeologists determined to identify Mithraea when the evidence leads them in the opposite direction.
 The most recent and daring theory for the explanation of the origin of Mithraism comes from A. Mastrocinque, The Mysteries of Mithras: A Different Account. Tübingen, 2017.
 F. Cumont, Textes et Monuments Figurés relatifs aux Mystères de Mithra, vol. I. Brussels, 1896. 404
 J. Alvar, “El Culto de Mitra en Hispania”, Memorias de historia antigua 5 (1981) 51–72.