With the anthology The Medieval Iberian Treasury in the Context of Cultural Interchange historian Therese Martin presents reprints of previously published contributions from the project The Medieval Treasury across Frontiers and Generations: The Kingdom of León-Castilla in the Context of Muslim-Christian Interchange, c. 1050-1200 (2016-2018), which she led as PI. This expanded version was published in 2020 at the beginning of her second project The Medieval Iberian Treasury in Context: Collections, Connections, and Representations on the Peninsula and Beyond (2019-2022) in an illustrated open access version supplemented by a complete bibliography and various indexes. Each of the nine articles focuses on the treasure of San Isidoro in León, which is examined from different perspectives by the individual contributors.

Overall, the book provides an intensive insight into an interdisciplinary and international research project with a very high co-operative component. This is made clear by the numerous references to the texts of the other authors in the volume as well as by the acknowledgements and, above all, by the introductory contribution by the editor and project leader herself.

In the introductory article, Therese Martin explains the background to the two projects and weaves together their history and genesis.

In her second article, she presents various objects made of silver and ivory, such as the cross of Fernando and Sancha (1063?) or the so-called Beatitudes Casket (late 11^th c.? /14^th c.). As remarkable and fascinating as the individual objects are, Martin does not focus on them as works of art, but as part of the material heritage, which, taken together with the textual records, provide information about their role within a royal monastic collecting strategy. The entirely new findings on the Beatitudes Casket are particularly impressive. According to Martin’s holistic analysis, the present object is a 14^th century compilation made of fragments from three older caskets of Islamic and Christian origin. Here, as in several other contributions to the anthology, it becomes clear what a major role reusing, recycling and reframing of objects played in the pre-modern era.

The historian Ana Rodríguez analyses the chronicles of the Kingdom of Castile and León from the 11^th to the 13^th century about the treasures mentioned there. Her focus is less on the identification of individual treasure objects than on the question of how these were integrated into the narrative. Rodríguez concludes, that in order to contribute to the construction of royal power in the chronicles, the focus of the narrative was not on the intrinsic value of the objects, but on the fact that they could be used to talk about the diverse relationships that could arise in the process of their exchange (donation, purchase or theft).

Two contributions in the centre of the volume are devoted to the textiles in the treasure. The art historian and curator Ana Cabrera Lafuente examines the fourteen textiles from the collection of the San Isidoro Museum regarding their materials, dyeing and weaving techniques to re-evaluate their chronology and provenance. In addition to art-historical methods of analysing the fabrics and evaluating the written sources, she is also using radiocarbon analysis. The result is that the silk fabrics, some of which contain linen and metal threads, cover a wide time span from the 9^th to the 19^th century and a large geographical area, as they were made in Central Asia, the Near East, Byzantium and various parts of Europe. What is remarkable for Lafuente is that very few of the fabrics come from the Iberian Peninsula itself. The collection of textiles can be seen as evidence of León’s extensive contacts and network and of the collecting process which shaped the treasure into what it is today.

In her contribution, María Judith Feliciano also discusses the textiles and places them in their historical and cultural context. She compares the periods before and after the arrival of the relics of San Isidoro and elucidates what role the ensemble played in the veneration of the saint in Castile and León and in the legitimisation of the monarchy.

The article by art historian Jitske Jasperse focuses on the portable altar (1144) of the Infanta Sancha (ca. 1095-1159), which is to be embedded together with her in a network of people and places between León and the Levant. To achieve this, Jasperse first analyses the inscription, the iconography and the material of the altar independently before combining various aspects at a later stage. With this approach, she clearly wants to make a plea for art history, because “it helps to illuminate why iconography, style, and material should matter to all medievalists” (p. 148). Finally, it becomes clear how this multicoloured and multilayered object testifies to Sancha’s connection to the Holy Land and an elite circle of leading figures of the Second Crusade.

In her article, art historian Pamela A. Patton draws attention to an unusual wall painting (early 12^th c.) in the so-called “Panteón de los Reyes” in San Isidoro in León, which shows Satan in a gentle, childlike form with dark skin and wearing a white, Fatimid-like silk robe. Patton begins by tracing the image tradition of a dark-skinned devil and discusses various examples from book and wall painting. She then focuses on the precious white robe and sees a reference to the Ṭirāz, courtly robes made of a white cotton-linen or a linen-silk mixture with embroidered Arabic inscriptions, such as the veil of St.-Anne (Apt, Cathedral of Ste.-Anne, Ṭirāz dated 1097; Fig. 7.9). Patton rejects the idea that 12^th-century viewers saw anything Muslim in this Satanic figure; instead, they would have perceived him simply as an Aethiops. The author finally places the mural in its spatial context and argues that it was primarily intended for a palatine audience.

Julie A. Harris focuses in her article on the search for the involvement of the Jewish community of León in the compilation of the church treasury of San Isidoro, as such cases have been proven in other areas of the Iberian Peninsula and Europe. There is no evidence of it in the case of San Isidoro, but the Jewish community was involved with donations for the altar lighting in the cathedral of León.

The small, perforated cylinder of red deer antler in the so-called Mammen style (late 10^th to early 11^th c.) is the only object of Scandinavian origin in the treasure of San Isidoro. Art historian Nancy L. Wicker focuses on this vessel that is less than 5 cm in size and uses motivic and stylistic comparisons as well as a praxeological approach to show that this elaborately decorated container combines influences from two worlds: the carved ornament is clearly of Scandinavian origin and the cylinder was also made there. However, its function as a perfume container for a solid fragrance is unusual among the Vikings and suggests that the vessel was made specifically as an export piece for the Iberian, oriental-influenced cultural area. It could have come to the Iberian Peninsula during the migration due to marriage of a noblewoman from the north.

There are hardly any serious objections to the anthology as a whole: A geographical map or a genealogical table could have conveyed a better understanding at one point or another, some pictures could have been larger (Fig. 2.5) or cropped differently (Fig. 2.4A), but these are minor observations that do not seriously detract from the pleasure of reading.

In conclusion, this enjoyable read presents important new findings and exemplifies how well international and interdisciplinary research can come together and succeed.