In the 1990s a guide hired by the Spanish tourist office took me to the last standing synagogue in the Spanish city of Segovia, which is now the Church of Corpus Christi, the home to an order of cloistered Franciscan nuns. Although the main gallery had been heavily restored after a fire in 1899, the building’s origins were still evident in the mudejar-inflected arches—as well as, the guide said, in a painting depicting the miracle that led to its transformation from a Jewish site of worship into a Catholic one. This happened in 1410, when, according to the story, a priest asked a Jewish doctor for a loan. In exchange the Jew demanded a consecrated host, which he tossed into a cauldron to boil. But the Blessed Sacrament rose in the air and flew to a nearby church. The painting, which was clearly made hundreds of years later, shows bearded men running away from the synagogue. “It’s only a legend,” the guide said. “But it’s pretty.” It was later that I learned Segovia’s court doctor, Meïr Alguades, had been killed for desecrating the host.That was the role of Jews in Spanish art in a nutshell, it seemed: their own creations desecrated, destroyed, or lost, their image tied to sacrilege and evil. In Spain, where national narratives did not make room for Jewish and Muslim influences until lately, there has been little incentive to look deeper. But strangely enough, the origins of Spain’s greatest surviving legacy of Jewish art—illuminated Haggadoth—have not been properly addressed even by Jewish scholars, says Vivian Mann, who runs the master’s program in Jewish Art and Visual Culture at the Jewish Theological Seminary in New York.But that’s because no one knew where to look—or what to look for, says Mann. The answer, she says, is in the retablos, Haggadoth, ceramic Judaica, and other suggestive objects borrowed from major collections in the United States and abroad for “Uneasy Communion: Jews, Christians, and the Altarpieces of Medieval Spain,” a fascinating, provocative show opening this week at the Museum of Biblical Art in New York. “We should be considering Haggadoth not as an isolated phenomenon of Jewish art,” Mann says, “but in the context of Spanish art.”The exhibition reflects a change in thinking about the role of Jews in Spain, specifically in the century between the countrywide pogroms of 1391, which decimated many communities, and the Expulsion, in 1492. It re-envisions Jews not as marginalized, passive victims, but as active protagonists in a cultural apparatus that was a great deal less segregated than was previously thought, working in studios composed of Christian, converso, and Jewish artists, who could turn out a Haggadah just as readily as they could a Catholic altarpiece.Mann, who has logged plenty of time in Spain—she was chief curator of the groundbreaking 1992 exhibition “Convivencia” when she was curator of Judaica at the Jewish Museum—got the idea for the show in the Aragonese town of Ejea de los Caballeros. “I was staring at a painting of the presentation of Jesus,” she says. “I said, ‘What’s that on the altar?’ It was a tik, or Torah case.” The object, which had gone unrecognized by scholars of Spanish medieval art, could not have been painted without knowledge of Jewish religious practice. She soon identified more tiks, along with other examples of a material culture lost to history in Spain but preserved in the Sephardic diaspora, such as a dress reminiscent of Moroccan Jewish bridal wear and a type of half-moon circumcision knife known in Amsterdam and Prague. She found paintings inscribed with correct Hebrew. The excavation of the Jewish quarter of Lorca, a town in the southern Spanish province of Murcia, further bolstered her thesis; the synagogue unearthed there looked just like the one in the anonymous 15th-century Catalan tempera-and-gold Christ Among the Doctors, which is on loan to the show from the Metropolitan Museum of Art.The Jewish contribution to Christian altarpieces is half of the equation; the contribution of Catholic artisans to Jewish manuscripts is the other. Mann is not the first to suggest that Jews, Christians, and conversos worked together in inter-religious ateliers—Harvard art historian Millard Meiss proposed as much in the 1940s. But she is the first to do extensive comparative research in the two genres. She found that figures and colors in the late-13th-century Hispano-Moresque Haggadah from Castile, the earliest known Passover manuscript, resemble those in the late-13th-century Scenes from the Life of Christ, a retablo in the collection of the Metropolitan Museum. Depictions of the Creation in the most lavish Passover manuscript of the era, the circa 1320 Golden Haggadah, echo those in another Met retablo, an anonymous 14th-century artist’s Scenes from the Life of Saint Andrew. “When I walked into the Cloisters storeroom, I almost fainted,” Mann says.Images of Jews in Spanish medieval art serve several purposes. Clearly they are stand-ins for the contemporaries of Jesus, just as the synagogues in the paintings are stand-ins for the Temple. But many figures also appear to be faithful portraits of individuals, whose stereotypically ruddy features contrast with the idealized images of Jesus, Mary, and the saints, making the latter look all the more holy in comparison. The red, unkempt locks and long beards worn by Jews in the retablos were considered signs of evil, but also reflected contemporary reality, namely sumptuary laws passed in 1412, which mandated that Jews had to let their hair grow wild. In the exhibition catalogue, Mann suggests that one reason the laws were passed is that in fact the Catholic and Jewish populations looked so much alike.In December I went to hear Mann speak on this subject at a conference, “The Jews of Spain: Past and Present,” sponsored by the American Sephardi Federation/Sephardic House. Representatives sent by city halls and tourist offices in towns across Spain, where Jewish cultural tourism has been growing steadily, were in the audience. In many cases, however, the historical evidence far surpasses the material traces of the Jewish presence. Indeed, last month, some towns along the Ruta de Sefarad discussed standardizing their offerings and ways to promote them: charming inns in former juderías, signage reflecting the Jewish presence of yore, knowledgeable tour guides, restaurants serving Jewish-style food. In Segovia, for example, you can dine at El Fogón Sephardí, in case you’d rather skip the city’s famous suckling pig, after you visit the “Centro Didáctico” in the judería. Also, according to a report in the local paper last month, the city government is working to market the Jewish cemetery as a “first-class” tourist attraction.So far, Mann says, there are no travel plans for “Uneasy Communion.” But it would be an interesting project for a Spanish museum—or a Jewish one.\n\nRobin Cembalest is the executive editor of ARTnews.Robin Cembalest is executive editor of ARTnews. She blogs at letmypeopleshow.com. Her Twitter feed is @rcembalest.