A few years ago, Ben and Will sat down with Dr. Thomas E. Burman, Professor of History at the University of Notre Dame and former Director of the Medieval Institute. Dr. Burman’s work focuses on the cultural and intellectual exchange between Jews, Christians, and Muslims in the medieval Mediterranean world. He is the author of Religious Polemic and the Intellectual History of the Mozarabs: c. 1050-1200 (1994), Reading the Qur’ฤn in Latin Christendom, 1140-1560 (2007), and most recently, he co-authored, with Brian A. Catlos and Mark D. Meyerson, The Sea in the Middle: The Mediterranean World, 650-1650 (2022), which retells the history of the medieval west by foregrounding the Mediterranean Sea as a site of religious and cultural cross-pollination.
Dr. Burman discusses with Ben and Will how he and his co-authors came upon the idea for this book, how they decided on the date range of 650 to 1650, the actual process of co-authoring, what they hope it can be used for in the classroom, and more. Building on Burman’s insistence that we come to see the Middle Ages as a time of intersecting religious and cultural influences (not unlike the modern world), they conclude by discussing the future possibilities of narrating a Eurasian or even global history of the medieval world.
A few years ago, Ben and Will sat down to chat with Dr. Michelle P. Brown, Professor Emerita of Medieval Manuscript Studies at the School of Advanced Study, University of London and the previous Curator of Illuminated Manuscripts at the British Library. She has published numerous books, key among which are works on Bede, the Lindisfarne Gospels, and the Luttrell Psalter. Their conversation with Dr. Brown was so rich that it was deemed worthy of two whole episodes!
The focus of their conversation was Bede the Venerable, especially in relation to Dr. Brown’s then-forthcoming book, Bede and the Theory of Everything. Bede was a Benedictine monk of the twin monastery MonkwearmouthโJarrow in Northumbria, England. He is famous for his work Historia ecclesiastica gentis Anglorum (EcclesiasticalHistory of the English People), a work that proved central to the formation of the English identity, and which has, over time, earned Bede the title, “Father of English History.”
Dr. Brown is a well of information on the life and writings of Bede, but she is equally full of insight intoโwhat is, for herโthe vocation of medieval studies. She speaks of moving into the world of Bede, coming to see every individual artifactโno matter how mundane it may at first appearโas an “individual witness” with its own biography. For her, “every pot shard matters.” Every shred of history is irreducibly unique and, in that way, a clue to the whole.
The curious story of the re-founding of the city of Tralleis into Andronikopolis by the soon-to-be-emperor Andronikos II Palaiologos and its quick demise at the hands of the Turkish founder of the Meneteลe Beylik contains a bit of Byzantine speculation on a geological process: the movement of groundwater.[1]ย The citizens of the rebuilt city, once besieged, found themselves unable to draw water from wells.ย The source of this story, George Pachymeres, offers a naturalistic explanation for why the city could be so easily driven to thirst (Chronicle I.191, starting with โThe cause, I think, was the porous nature of the plainโฆโ):
To summarize his explanation, Pachymeres images an entire underground water cycle, whose movement was a geological game of โkeep awayโ from the depths, where it was needed to pool before being drawn by the thirsty people of Tralleis (see Fig. 1, Right). It is an elegant and sophisticated natural explanation for a writer who did not benefit from the advances in geological scientific thinking since the thirteenth century. The explanation has interesting interactions with modern geological explanations for groundwater movement through aquifers. An aquifer is a body of saturated rock or sediment through which water can move easily. Moreover, Pachymeres is really describing an unconfined shallow alluvial aquifer. Unconfined aquifers โ named so because no layer of impermeable material stood between the aquifer and the surface – were dependent upon the level of water in the water table (Fig. 1, Left). Such aquifers are common in river environments in the alluvial soil deposited by the river itself. The Byzantines themselves called alluvial soil โyellowโ or โriverineโ in the Geoponika (a Byzantine treatise on agriculture written entirely from older texts)[2] and in land survey manuals used by bureaucrats to calculate tax and lease rates.[3]
Figure 1 Conceptual Ground-water Flow Diagrams.ย Left, by the USGS (https://www.usgs.gov/media/images/conceptual-groundwater-flow-diagram).ย Right, edited by myself, following Pachymeres.
Aquifers are defined by permeability and porosity. Porosity is how much water a portion of rock or sediment can hold. Loose gravel has high porosity while solid granite has low porosity. Permeability on the other hand is how easily water can move through that same aquifer. For instance, caves in limestone are very porous, but too permeable to hold water for long. Pachymeres is specifically describing the Maeander valleyโs alluvial soil as highly permeable (ฮผแฝด ฯฯฮตฮณฮฑฮฝแฝธฮฝ, โnot water-tightโ or literally โunroofedโ). While permeability can vary among alluvial soil, based on the amount gravel, sand, or clay, such aquifers can be depleted quickly by many factors, including evaporation โ even if Pachymeresโ image of ground water movement via evaporation appears too much like the siphon effect. Either way, these aquifers were not reliable in the summer. Still, Pachymeres appears to invert the water table. Water can only be found in the shallowest places, because he needs to explain why citizens of Tralleis cannot draw water but their crops flourished (Fig. 1, Right).
Figure 2 Map of Geological Features in the Region Around Tralleis (Map made by Author in QGIS).
However, Pachymeresโ vision of groundwater movement is complicated by the fact that the alluvial plain and the land underneath Tralleis are not the same (Fig. 2). The location of the city is known from archaeological work in the nineteenth century,[4] while Tralleis has been subject to more continuous excavation since 1996 under a series of directors from Adnan Menderes University. The ground of both locations was formed by alluvial processes tied, not to the river itself, but to the mountain streams flowing down from the mountain of Messogis (modern Aydฤฑn Daฤlar). These streams deposited their dissolved soil at the base of the mountain creating what is called an alluvial fan. The numerous fans on the southern slopes of Messogis blend together into a singular strip stretching from Tralleis to the Maeander River (Fig 2, diagonal hatched lines). The fundamental difference between the ground upon which Tralleis sits and the alluvial plain is when it was formed by an alluvial fan. The conglomerate rock upon which the entire city stood (Fig. 2, crossed hatched lines) was formed by alluvial forces 400,000 years ago in the late Pleistocene, i.e., when woolly mammoths still walked the earth.[5] In fact, the alluvial fans that formed this conglomerate are so old that seismic forces have shifted them upwards in the landscape since then. The Eudonos Stream (modern Tabakhane รayฤฑ) actually cuts a canyon through it. One can productively compare the geological situation at Tralleis with the city of Sardis in the Hermus river valley to the north. The acropolis of Sardis was built upon the โSart formation,โ another bit of Pleistocene, alluvially-formed conglomerate that was thrusted upward by seismic forces.[6]
I do not compare this medieval explanation with modern geology to shame Pachymeres.ย If anything, that such a deep dive into modern geology is required to understand the extent to which this explanation does error, should be seen as a sign of its elegance and sophistication.ย
Tyler Wolford, PhD Byzantine Studies Postdoctoral Fellowship Medieval Institute University of Notre Dame
[1] George Pachymeres, Chronikon I.191; Albert Failler, ed., George Pachymรฉrรจs Relations Historiques I. Livres I-III. Paris, 1984, VI.20, pg. 595, line 12-29, pg. 597, lines 1-3, See also the discussion of this phenomenon in Peter Thonemann, The Maeander Valley: A Historical Geography from Antiquity to Byzantium. Cambridge, 2014, 1-4.
[2]Geoponika II.9. For an English translation see Andrew Dalby, trans. Geoponika: Farm Work. Prospect Books, 2011, 79.
[3] J. Lefort, R. Bondoux, J.-Cl. Cheynet, J.-P. Grรฉlois, V. Kravari, ed., Gรฉomรฉtries du fisc byzantin. Rรฉalitรฉs byzantines 4. Paris, 1991, Paragraph 4, 8. For more on the Byzantine tradition of land survey, see my earlier entry in the Medieval Instituteโs blog: https://sites.nd.edu/manuscript-studies/2024/12/25/a-cord-laid-tight-loosens-discord-the-shifting-role-of-precision-in-the-byzantine-landsurvey-tradition/
[4] C. Humann and W. Doerfeld, โAusgrabungen in Tralles,โ Mittheilungen des Kaiserlich Deutschen Archaeologischen Instituts. Athenische Abtheilung 18 (1893): 395-413.
[5] Emrah รzpolat, Cengiz Yฤฑldฤฑrฤฑm, and Tolga Gรถrรผm, โThe Quaternary Landform of the Bรผyรผk Menderes Graben System: the Southern Menderes Massif, Western Anatolia, Turkey,โ Journal of Maps 16.2 (2020): 407-411.
[6] Gรผrol Seyitoฤlu, Nicholas D. Cahill, Veysel Iลฤฑk, and Korhan Esat, โMorphotectonics of the Alaลehir Graben with a Special Emphasis on the Landscape of the Ancient City of Sardis, Western Turkey,โ in Landscapes and Landforms of Turkey, ed. Catherine Kuzucuoฤlu, Attila รiner, and Nizamettin Kazancฤฑ. Springer, 2019, 495-507.
