Identifying A Dye Source In A 15Th Century Medieval Tapestry

As detailed in a new article in Heritage, analysis with liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-qToF-MS) revealed the presence of several multiply chlorinated xanthones that are produced only by certain species of lichens. Various lichen dye sources have been documented in the literature for centuries and are classified as either ammonia fermentation method (AFM) or boiling water method (BWM) dyes based on their method of production. However, none of these known sources produce the distinctive  metabolites present in the Heroes tapestry. The researchers also used LC-qToF-MS to compare the chemical composition of the dyes in the tapestry with that of several species of crustose lichen. They definitively identified lichen metabolites, including thiophanic acid and arthothelin, based on comparison with lichen xanthone standards, and a reference of Lecanora sulphurata, confirming the presence of a lichen source. This is the first time that evidence of lichen dye from a variety of species has been found in a historic object, and also the first evidence that boiling water methods were used before the 18th century.
Background from the Met: The motif of Nine Heroes drawn from Classical, Jewish, and Christian traditions was first mentioned in a French poem in 1312, and soon became a popular theme throughout art and literature in late medieval Europe. Pulled from both history and legend, Hector of Troy, Alexander the Great, and Julius Caesar represented the Heroes of the Classical era. Joshua, David, and Judas Maccabeus, from the Hebrew Bible and related accounts, constituted the Jewish Heroes. Finally, from medieval Europe, King Arthur, Charlemagne, and Godfrey of Bouillon formed the Christian Heroes. Celebrated as perfect embodiments of chivalry, the Nine Heroes provided exemplars of worthy warriors and just leaders for men of the noble and upper classes.Dating to around 1400, The Cloisters’ Heroes are among the oldest surviving medieval tapestries in the world. Their state of preservation is remarkable, even though only five heroes are still extant. Made entirely of wool, these hangings were both decorative and practical, keeping stone interiors warm and festive during the colder months of the year.Since the acquisition of the Heroes Tapestries, scholars have suggested that they may have been made for Jean, duke of Berry (1340–1416), son of John II, King of France. Of the fourteen heraldic banners in the upper part of the Hebrew tapestry, ten display Jean’s coat of arms. Of the remaining four, three show the royal arms of France and one the arms of Jean’s younger brother, Phillip the Bold, duke of Burgundy. Tantalizingly, inventories of the collections of the duke of Berry indicate that he did own tapestries featuring the Nine Heroes, but these hangings—unlike those in The Cloisters’ collection—were made with gold and silver threads. Although Met’s tapestries may have resembled the the duke’s, there is no conclusive proof regarding their original ownership.In this tapestry, Julius Caesar wears the imperial crown and brandishes a falchion, a specialized single-edged saber. A shield bearing a double-headed eagle, signifying the ancient Roman Empire, hangs from a spear at his side. He is surrounded by musicians and foot soldiers whose blue apparel and accessories mimic Caesar’s regal role. Originally, Julius Caesar would have been part of the Classical Heroes tapestry alongside Hector of Troy and Alexander the Great. Another tapestry preserved at The Met Cloisters (47.101.2d) most likely depicts Hector, or possibly Alexander; the third hero does not survive. The Julius Caesar tapestry is currently off view and undergoing an intensive treatment in the Museum’s Department of Textile Conservation.
May 10. 2024