The al-Andalus Glass Project is directed by Chloe N. Duckworth and David J. Govantes-Edwards, and seeks to investigate the production, trade and consumption of glass in the medieval Iberian Peninsula, from the Visigothic through to the Christian periods, but with a particular focus to date on Islamic Spain.
Barthelemy, P. 2002. La Sedacina ou l’Oeuvre au crible. L’alchimie de Guillaume Sedacer, carme Catalan de la fin du XIV siecle. Paris: SEHA-Arche.
[Some of the ideas and techniques described by the Catalan monk may also be relevant to the preceding technology under Islamic rule.]
Carmona, N., Angeles Villegas, M., Jimenez, P., Navarro, J. and Garcia-Heras, M. 2009. ‘Islamic glasses from al-Andalus: characterisation of materials from a Murcian workshop (12th century AD, Spain)’. Journal of Cultural Heritage 10: 439-45.
Coll Conesa, J. 2003. ‘Transferencias técnicas en la producción cerámica entre al-Andalus y los reinos cristianos: el casade Sharq al-Andalus. Cerámicas islámicas y cristianas a ﬁnales de la Edad Media. Inﬂuencias e intercambios 4. Museo de Ceuta, Ceuta. pp. 301–65.
Córdoba, R. 2014. ‘Technology, craft and industry’. In M. Valor and A. Gutiérrez (eds.) The Archaeology of Medieval Spain 1100-1500. Sheffield: Equinox. pp.100-116.
Cressier, P. (ed.) 2000. El Vidrio en al-Andalus. Casa de Velázquez, Madrid.
Duckworth, C.N. 2017, in press. ‘Glass in medieval Spain: a long-term perspective on knowledge transfer’. Annales du 20e Congrès de l’Association Internationale pour l’Histoire du Verre. Fribourg: AIHV.
Duckworth, C.N. and D.J. Govantes-Edwards. 2017, in press. ‘Glass production and technology in al-Andalus’. In Mercedes Delgado Pérez and Luis Gethsemaní Pérez Aguilar (eds.) Economía y sociedad en al-Andalus
Expósito Capilla, R. 2006. ‘Excavación arqueológica de urgencia en c/Cerrojo 32’. Anuario arqueológico de Andalucía 2006: 3358–71.
Fernandez-Puertas, A. 1998. ‘Gilded and enamelled glass in al-Andalus’. In R. Ward (ed.) Gilded and enamelled glass from the Middle East. London: British Museum Press.
Frothingham, A.W. 1963. Spanish Glass. London: Faber and Faber.
[This book makes many useful citations of historical references to furnaces of the 15th century and later, particularly in Catalonia.]
García Heras, M. 2008. ‘Estudio arqueométrico de los vidrios andalusíes procedentes del taller de la calle Puxmarina (Murcia), Vendolay’. Revista del Museo Arqueológico de Murcia 11: 277–302.
García Sandoval, J. 2010. Lorca: luces de Sefarad. Murcia: Editorial Regional de Murcia. [Includes mention of glass lamps from a synagogue.]
Glick, T.F. (1979) Islamic and Christian Spain in the Early Middle Ages. Princeton, NJ: Princeton University Press.
[Includes a brief section on glass.]
Govantes-Edwards, D.J. 2017. ‘Two new glass furnaces in Spain’. Glass News 41: 8-10.
Govantes-Edwards, D.J., Duckworth, C.N. and Cordoba, R. 2016. ‘Recipes and experimentation? The transmission of glassmaking techniques in Medieval Iberia’. Journal of Medieval Iberian Studies 8: 176-95.
Govantes-Edwards, D.J., C.N. Duckworth, R. Córdoba de la Llave, L. Aparicio Sánchez and C. Camacho Cruz 2016. ‘El estudio del vidrio andalusí y las posibilidades de estudio en su composición química: primeros resultados y posibilidades’. Boletín de Arqueología Medieval 18: 31-50.
Govantes-Edwards, D.J. and C.N. Duckworth 2015. ‘El análisis químico de vidrios y vedrios de la Málaga islámica. Estudios en tecnología medieval’. Note. Mainake XXXIV.
Jiménez Castillo, P., Navarro Palazón, J., and Thiriot, J. 1998. ‘Taller de vidrio y casas Andalusíes en Murcia: la excavación arqueológica del Casón de Puxmarina’. Memorias de Arqueología 13: 419–58.
Rontomé Notario, E., and Pastor Rey de Viñas, P. (eds.) 2006–7. Vidrio islámico en al-Andalus: real fábrica de cristalesde la granja. Cuenca: Fundación Centro Nacional del Vidrio.
Whitehouse, D. 2006. ‘The “Epistola Abbreviatoria”: a description of glassmaking in Renaissance Spain’. Annales du 17e Congrès de l’Association Internationale pour l’Histoire du Verre. Antwerp: AIHV.
[The recipes presented are post-Islamic but may also be pertinent to the making of glass in preceding centuries.]
In November 2016, nine archaeologists fled the UK to spend two weeks in the occasionally challenging, but always stunningly beautiful landscape of Madinat al-Zahra in the foothills of the Sierra Morena mountains, near Cordoba, where we were joined by a brilliant and enthusiastic team of local students from the University of Cordoba.
Our aim? To understand the urban layout of the site, using state-of-the-art, non-invasive techniques (of which more below), and to identify the location of high temperature workshops which served the palace and city.
The site, which consists of a palace and an accompanying city (madina), was built in the 10th century CE, by Abd al-Rahman III as a declaration of his power. He was the descendant of the Umayyads, the dynasty which had once ruled over the entire Muslim world, before being overthrown by the Abbasids in 750 CE. This turn of events caused the last surviving heir of the dynasty, Abd al-Rahman I, to flee to the Iberian Peninsula and set up independent rule in this far western outpost of the Islamic Empire.
But it was not until the Abbasids themselves were threatened, now by a new dynasty (the Egyptian Fatimids) that the leader of al-Andalus (in 928 CE) declared himself to be the rightful caliph, and heir to the Islamic world. As part of this declaration, he constructed a new palace and city. These are the origins of Madinat al-Zahra, ‘the shining city’.
A Buried City
Unlike the majority of cities built in the Islamic world at this time, the site was short-lived, with turmoil following the death of Abd al-Rahman III finally leading to its destruction and abandonment in the first decades of the 11th century. The palace was excavated in the early twentieth century, but almost none of the madina has been touched, preserving in tact its urban layout and revealing much about the intentions of those who constructed it. Today, it is protected land, grazed by a large herd of cows, and occasionally visited by greyhounds on a hare-hunt.
The exceptional nature of the remains means that any archaeological intervention has to be sensitive to their continued preservation. Regardless of whether such a site were ever to be excavated, much can be learnt about it with the use of non-invasive survey techniques, which allow us to ‘see’ beneath the ground, as well as plotting the topography of the site and the chemistry of the soil. We have begun to map the urban layout as it is preserved today; and have started to find evidence which could relate to the locations of the workshops that produced the fabulous architecture or luxury goods of the palace, and the equipment required by the extensive military housed at the site.
How to See without Digging
The main technique we used was magnetometry. This technique measures, and allows us to map, patterns of magnetism in the soil. Buried features will affect the patterns, which is how the technique allows us to identify buried walls, ditches, and – importantly for us -areas which were subjected to high temperature in the past, including ovens and furnaces. We set up grids, spatially rooted to cardinal points by GPS, and the magnetometer operators (carefully kitted out in entirely non-magnetic clothing) walked systematically across them, recording the changes in the signal. These records are then downloaded and a computer is used to map them and link them to the results from previous days and other known information about the site.
Chemical mapping was done by the use of handheld pXRF – this technique fires X-rays at whatever is immediately in front of it, and by reading the returned signals is able to identify what elements are present. The use of handheld pXRF in this way was originally pioneered by Dr Roger Doonan of the University of Sheffield, and is championed at Madinat al-Zahra by our own Dr Derek Pitman. The technique has traditionally been used to read the chemistry of objects, particularly metals. The genius of using it to find the location of production sites is that it can be placed directly onto the ground in order to identify areas of the soil which were polluted by metals in the past. High concentrations of metals not only suggest that some industrial activity may have taken place in a particular location; they also help to ascertain what kind of activity it might have been.
Chemical readings were taken in combination with magnetic susceptibility, which along with the XRF looks like something out of the original Star Trek (as demonstrated below by yours truly, in a fetching mac). Magnetic susceptibility is particularly useful for identifying where there may be a broader spread of burnt material, rather than an intensive concentration such as those picked up by the magnetometer. Finally, a topographic survey was conducted by Chris Caswell, in order to map the present ground surface, which is also related to the location and identify of buried features. These are only a selection of the arsenal of non-invasive survey techniques now available to the archaeologist. They key in any work is to tailor the choice of techniques to the site in question, as well as – somewhat unavoidably – the budget available!
Oy! You Mentioned Game of Thrones..?
We had a stupendous season, and the results are already being prepared for publication (watch this space). On a free Sunday, I was able to visit one of the quarry sites from which materials had been taken to construct the palaces: it was a beautiful place, with the marks of quarrying still clearly visible in the rock.
But okay, since you ask: non-archaeological highlights included learning that while we were there, the area was full of Game of Thrones actors, who were filming at the nearby site of Almodovar del Rio, a stunning restored castle seductively visible from Madinat al-Zahra. We weren’t quite close enough to offer any spoilers, but where would be the fun in that?
In July 2016, five students from the University of Leicester accompanied us for our two week excavation season in the secano, the area of the Alhambra where a number of workshops and furnaces are located, as part of the Alhambra Royal Workshops Project. The aim of the project is to learn about how the decorative tiles and other fabulous objects of the royal palaces were made. They joined the experts in our team, led in the field by Ben Moore and Eleonora Montanari, and worked alongside Dr Alberto Garcia Porras and his postgraduate students from the University of Granada, for our first ever ‘trowel to ground’ field season.
We opened two trenches, located on either side of one of the main tourist walkways. In both trenches, the remains of furnaces were already visible, and we wanted to excavate them to understand more about the date of the furnaces, and their relationship to surrounding structures.
The Leicester students were working in a relatively sheltered spot close to the reconstructed walls of the Alhambra. Here the topography is very uneven, so we were constrained to excavating a strip of land running approximately east from the remains of a furnace. The archaeology here was very shallow, but it was clear from our work that we had some sealed contexts, lying over a number of structures which related to workshop and habitation sites. They postdate the Muslim phase of occupation at the site, and provide instead an important insight into its organisation under Christian rule.
Meanwhile, Alberto’s team were far more exposed to both the sun and the tourists. They were working in a more heavily reconstructed area, clearly visible from one of the main walkways through the site. Visitors to the site were able to witness archaeology in action, with all the sweat and toil that it involves! Working under such scrutiny was just a tiny bit like being in an archaeological zoo, but it was great to see how interested people were in what we were doing. Chatting to visitors from many parts of the world including Spain, Italy, France, Morocco, the US and the UK, we got some great feedback, too:
“It was inspiring to see that there was so much … that we do not know about” (Kamalia Roubat)
“The Alhambra is an active excavation site … there’s so much more to discover” (Meri Escandon)
“Good to know that it is evolving and being looked after” (Lucy Fromings)
And, a personal favourite: “Archaeology is hard work” (Nico van der Gaag)
This area was previously subject to some reconstruction work and the archaeology was more disturbed than in the other trench, but we were still able to expose some information on the structure of the furnaces and the remains associated with them. When you work in pyrotechnology as I do, some of the most exciting finds are waste products which have been affected by heating – a bit of tile which was not glazed properly, or a deformed piece of kiln lining.
One of the innovative techniques that we are developing in the field is the use of handheld pXRF during excavation itself. The technique fires X-rays into the ground, allowing us to ‘read’ the chemical composition of the soil, which is immensely useful when we are investigating production sites – it basically lets us identify where chemical pollution is most intensive, and see which pollutants are present. Our resident pXRF expert, Dr Derek Pitman, couldn’t make it out this summer, albeit for rather a nice reason (the birth of his second daughter). But not to worry, as project director Prof. Kate Welham was ready to fill in with the pXRF in hand. She analysed the remains of vitreous materials found at the base of a furnace, and demonstrated that they were used for either glass or glaze production.
Of course, excavation is only the beginning. The results of this first field season demonstrate just how much more work needs to be undertaken at the site. We’re currently studying the pottery, bone, and industrial remains recovered, to understand more about the phases of occupation, and use of these two areas of the secano.
Not the Nine O’Clock News
It wasn’t just the tourists who were interested in us. Our hardworking students appeared on the cover of two local newspapers, and David Govantes Edwards made it onto the main national news slot one evening – the Spanish equivalent of the UK’s 9 O’Clock news. There are two types of archaeologist: those who run and hide whenever a camera is in sight, and those who thrive under the limelight. David certainly falls into the latter category, and he braved the many microphones and cameras to deliver a fantastic short piece on the work we were doing at the site, which went out to viewers across Spain that evening.