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RAE 2008

Rearch Assessment Exercise 2008

Edward Cooper
La Mitra y la Roca - intereses de Alfonso Carrillo, arzobispo de Toledo, en la ribera del Ebro

Authored book

Exclma. Diputación Provincial de Toledo
ISBN: 84-87100 73 2

179 pages

co-author: Salvador Mirete Mayo

Combining archival sources and laboratory analysis, this interdisciplinary study examines the sourcing of alum in Spain for the textile trade between the fall of Constantinople (1453) and the inauguration of the Papal mines of Tolfa (c1462), in the context of political events in the Rioja area of Spain where the resource studied was found. It has led to Cooper’s appointment as second supervisor to a Ph.D registered in the dept. of Mineralogy & Crystallography at Madrid University on 15th century alum extraction in the area of Rincón de Ademuz (Valencia, Spain) and related sites, as of February 15th 2006.

Alum was crucial in the dyeing of quality woollen cloth, and this interval of supposed dearth has hitherto been completely ignored.

Cooper wrote most of the text, photographed sites and buildings, carried out the historical research and prospected the samples. S.Mirete Mayo, a leading Spanish mineralogist, photographed and analysed the samples and provided geological input.

Cooper’s previous research has examined mediaeval fortified architecture in the Iberian Peninsula, and related historical events. La Mitra y la Roca deals with an alum mine located in the demesne of a significant castle of the period, and develops the subject in a new direction through interdisciplinary research. Similarly interdisciplinary, and also rooted in fortification, was the research of the Ph.D candidate Cooper supervised over this period, on the early development of gunpowder artillery (award October 2007).


J. García Turza (Berceo 142 pp. 269-271)
F.-J. Ayala Carcedo (Boletín Geológico of the Instituto Geológico Minero de España, May 2002 pp. 111-112)
M. Diago Hernando (Anuario de Estudios Medievales vol. 32 no. 1 (2002) pp. 531-2).

English abstract:

The Turkish capture of Constantinople (1453) starved the woollen industry, economic backbone of Christendom, of alum. It coincided with the disgrace and execution of Álvaro de Luna, favourite of John II of Castile.

In 1459, henchmen of his son-in-law, Juan de Luna, lord of Cornago (Rioja) assassinated adherents of the Spanish primate, Alfonso Carrillo de Acuña, archbishop of Toledo, from the converted Jewish community of Soria, hub of the sheep droving network. Luna then fled Cornago, abandoning his wife. The archbishop encroached on Cornago, and commenced extracting alum.

Historically, only volcanic rock, of the appropriate composition, has been thought to yield commercial alum. The fossil rich Rioja area is clearly non-volcanic.

The survival of "Casacarrillo" as the name of a smallholding, and vestiges of refining activity in the terrain, enabled location of the alum workings. The precise geological strata capable of yielding alum, aided by the gradual subterranean formation of dilute sulphuric acid through degradation of pyrites, turned out to be a combination of pyrophyllite (the basis of talcum) and jarosite ((SO4)4(Fe.20H)6Ka2).

The refinement process of this naturally formed incipient alum is unknown, since that used for volcanic formations would not apply. The uncertainty of Ottoman supplies from Anatolia made any effort profitable. Several theories are advanced regarding how the deposits were first located in the absence of any historical precedent. The archbishop had a political agenda, relating to the eventual unification of the Spanish kingdoms, explaining his need for the gold that participation in the international alum trade could bring him. In 1468 he was implicated in the assassination of the bishop of nearby Pamplona (Navarre) and, although the see remained vacant for 5 years, he then secured it for a nephew, the first step in the political union of Castile and Navarre in 1512.

Please also refer to hardcopy item for this output.

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