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Das Scheitern des Kalifats

Vor 1300 Jahren begann im August 717 die arabische Belagerung Konstantinopels. Der US-amerikanische Autor Harry Turtledove spielte 1989 in seiner Kurzgeschichte „Islands in the Sea“ mit der Idee einer arabischen Eroberung Konstantinopels im Jahr 717, die zu einer Dominanz des Kalifats in Osteuropa und zur Islamisierung anstelle einer Christianisierung der slawischen Welt führt. Doch auch jenseits solcher Spekulationen war der Versuch des Kalifats, das konkurrierende Imperium der Römer, als die sich die erst durch die neuzeitliche Forschung so bezeichneten Byzantiner verstanden, mit einem Schlag auszulöschen, eines der wichtigsten Ereignisse der Geschichte der Mittelmeerwelt.

Der Verlauf der Ereignisse und ihre Folgen können Sie in meinem Beitrag in der "Zeitreise" auf Die Presse-Online nachlesen:diepresse.com/home/zeitgeschichte/5273885/Das-Scheitern-des-Kalifats

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The timing of the crash

Temporal dynamics of medieval and modern banking systems

Johannes Preiser-Kapeller, IMAFO/ABF, Austrian Academy of Sciences

(Email: Johannes.Preiser-Kapeller@oeaw.ac.at)

Social Complexity and Financial Markets

In the last decades, the concept of complex systems has revolutionised our understanding of natural as well as social phenomena. Complex systems are understood as large networks of individual components, whose interactions at the microscopic level produce “complex” changing patterns of behaviour of the whole system on the macroscopic level; in the field of social systems, these patterns stem from the actions and interactions of individuals, ranging from families and small communities up to the globalized society of today (MILLER/PAGE, 2007; WHITE, 2008).

Most impressive examples of social complexity are financial markets, as has been explained for instance by the Swiss scientist Didier Sornette: “Financial markets constitute one among many other systems exhibiting a complex organization and dynamics with similar behavior. Systems with a large number of mutually interacting parts, often open to their environment, self-organize their internal structure and their dynamics with novel and sometimes surprising macroscopic (“emergent”) properties. (…) This view tends to replace the previous “analytical” approach, consisting of decomposing a system in components, such that the detailed understanding of each component was believed to bring understanding of the functioning of the whole. A central property of a complex system is the possible occurrence of coherent large-scale collective behaviors with a very rich structure, resulting from the repeated nonlinear interactions among its constituents: the whole turns out to be much more than the sum of its parts.” (SORNETTE, 2003, 15-16)

One of the most relevant questions is of course the resilience respectively the failure of social systems, since the impact of such phenomena on societies can be dramatic, as also most recent events (the financial crisis of 2008 and its aftermath) have demonstrated. While exogenous impacts (such as natural catastrophes) can stress or even over-stress the resilience of social systems, in the field of finances, most times “a crash has fundamentally an endogenous, or internal, origin (…) exogenous, or external, shocks only serve as triggering factors” (SORNETTE, 2003, 4). Therefore, while the interdependencies between a social system and its (complex) environment have to be analysed as well, the endogenous dynamics within the financial system shall be of primary concern: “Market crashes exemplify in a dramatic way the spontaneous emergence of extreme events in selforganizing systems. (…) Sudden transitions from a quiescent state to a crisis or catastrophic event provide the most dramatic fingerprints of the system dynamics. (…) Stasis and equilibrium are illusions, whereas dynamics and out-of-equilibrium are the rule. The quest for balance and constancy will always be unsuccessful. (…) The outstanding scientific question is thus how such large-scale patterns of catastrophic nature might evolve from a series of interactions on the smallest and increasingly larger scales. In complex systems, it has been found that the organization of spatial and temporal correlations do not stem, in general, from a nucleation phase diffusing across the system. It results rather from a progressive and more global cooperative process occurring over the whole system by repetitive interactions.” (SORNETTE, 2003, xv and 19; cf. also ALBEVERIO/JENTSCH/KANTZ, 2006, and TALEB, 2008, on extreme events; REINHART/ROGOFF, 2009).

Didier Sornette also states: “Crises are extreme events that occur rarely, albeit with extraordinary impact, and are thus completely undersampled and poorly constrained” (SORNETTE, 2003, 19-20). In this respect, historical analysis can contribute to an enlargement of our data basis on such events and their better understanding (cf. for a comparative approach also REINHART/ROGOFF, 2009).

 

A Complex Historical Analysis of Medieval Financial Markets

The origins of modern-day financial markets lie in the commercial centres of late medieval Italy (FERGUSON, 2008); in Florence, Genoa and Venice not only banks and banking techniques were developed, but also public borrowing via the emerging financial markets. In Florence, the first large mercantile and banking companies (“super-companies”) with far reaching networks of branches abroad were established at the end of the 13th century in order to answer to the requirements of large scale trade with grain and textiles and of the financing of the papacy and monarchs such as the King of England (RENOUARD, 1941; HUNT, 1994; NAJEMY, 2006; GOLDTHWAITE, 2009). Venice, otherwise a more conservative financial community, was on “the leading edge” for the development of giro and fractional reserve banking (meaning that funds deposited into a bank are mostly lent out, and a bank keeps only a fraction of the quantity of deposits as reserves, cf. GISCHER/HERZ/MENKHOFF, 2005) (LANE, 1973; MUELLER, 1997; STAHL, 2000). And Genoa saw the foundation of the first public bank in Italy in 1407/1408 (the “Banco di San Giorgio”), which offered “deposit taking, clearance and lending services” for privates as well as for the commune of Genoa (cf. esp. the studies of FELLONI; EPSTEIN, 1996). In all three cities, the growing pressure on public finance led to the establishment of a new form of public debt, “known as the monte because it was regarded literally as mountain-sized, consisting of shares issued by the commune, redeemable at its option, and paying a fixed low rate of interest.” (HUNT/MURRARY, 1999, 207; cf. also EPSTEIN, 2000; PEZZOLO, 2007; FERGUSON, 2008; STASAVAGE, 2011). These shares could also be sold and used as a form of private investment, thus increasing the complexity of financial markets.

Fig.: One page from the Libro delle Colonne of the Banco di San Giorgio in Genoa (1485; Archivio di Stato di Genova, San Giorgio, Colonne, Nr. 359)

 

Yet, these early financial markets soon experienced the systemic vulnerability to failures and crises up to extreme scales in a way similar to modern-day phenomena: between 1343 and 1346, the three largest Florentine “Super-Companies” of the Bardi, Peruzzi and Acciaiuoli all collapsed within 30 months, leading to major social upheavals in the city (HUNT, 1994; NAJEMY, 2006). The only survivor of similar scale, the Alberti Company, continued existence one more century, but in the form of a group of essentially independent branches in Florence and abroad, connected through family relationships. Companies of the scale of the Bardi or Peruzzi never again emerged in Renaissance Florence; also the famous Bank of the Medici (1397-1494) never achieved a similar predominance on the financial market as did its forerunners (DE ROOVER, 1966; ORIGO, 1985; HUNT/MURRARY, 1999; NAJEMY, 2006; GOLDTHWAITE, 2009). A different development we can observe in Venice; there, after a series of bank failures in the mid-14th century, banking houses became larger, also on demand of the legislator, who considered bigger companies less vulnerable to “unpredictabilities” such as bank runs and panics as well as better qualified to function as borrower to the state. But by these measures, in the medium term, bank failures become not only not less frequent, but also bigger (MUELLER, 1997; HUNT/MURRARY, 1999; PEZZOLO, 2006). Also in Genoa, the Banco di San Giorgio failed in 1444, because of “a lack of own capital necessary to face occasional liquidity shortages and insistent demands for money by the state which the bank could not turn down”; only in 1531, the bank would open its doors again (FELLONI; EPSTEIN, 1996; PEZZOLO, 2007; VALÍČKOVÁ, 2010). Therefore, an analysis of these three first emerging financial markets could substantially contribute to the complex dynamics of such social systems.

Fig.: A 14th century manuscript depicting bankers in an Italian counting house (British Library, Cocharelli, Cuttings from a Latin prose treatise on the Seven Vices: avarice)

 

Medieval Venice and the United States in Comparison: Methods and Results

The statistical analysis is based on binary time series (1 = presence of a major bank crash in that year, 0 = absence). Mean waiting times between years with events were calculated on the basis of an expectation test for a poisson process for simple columns of event times for the five phenomena. Probabilities of transition between years with events and years without were calculated with the help of Markov chain analysis on the basis of the above-mentioned time series. All calculations and graphs were done by the author with the help of the software programmes Microsoft-Excel* and PAST* (Version 2.17).

Figures: Frequencies (above) and histogramme of years with banking crises in Venice (blue) and the USA (red) during the 200 years periods

Interesting is of course the similar number of years with major bank failures and the similar mean waiting time between years with bank crashes in the two 200 years time series for Venice (1300-1500) and the USA (1800-2000). Both time series also show a certain cyclicity (which is more pronounced for the USA time series), indicating  comparable system dynamics up to a certain degree.

This is also indicated by the scalograms of wavelet transformations of the two binary time series; these scalograms help to identify cycles at various time scales (y-axis; a cycle at a scale of 4, for instance, indicates a length of 24  = 16 years, in our case) of different power (indicated with colours from blue [absent] to red [strong]) along the time line (x-axis) of 200 years (the black lines indicate the p = 0.05 significance level). We observe a significant increase in power for cycles at a scale of 4.2 = 18.38 years and upwards for the USA-timeline beginning from ca. 1900, for instance (which would be valid also for the interval between the bank crashes around 1990 and the most resent crisis starting in 2008). The 16 years cyclicity (at a scale of around 4 at the y-axis in the scalogram) for the Venetian time series is on the contrast less pronounced.

Fig.: Scalogram of the wavelet transformation of the binary time series of years with bank crashes
for Venice (1300-1500)

Fig.: Scalogram of the wavelet transformation of the binary time series of years with bank crashes for the USA (1800-2000)

Figure: Transition probabilities: years with major failures of banks in Venice (1300-1500)

Figure: Transition probabilities: years with major failures of banks in the USA (1800-2000)

 

Note the much higher transition probability between subsequent years of major bank crashes in comparison with the medieval Venetian time series, indicating a higher persistency of crisis periods once broken out in this modern day banking system of the United States.

Figure: Run on the Seamens Savings Bank during the Panic of 1857

 

Selected references

ALLISON, P. D.: Event History Analysis: Regression for Longitudinal Event Data (Quantitative Applications in the Social Sciences). Sage, London 1984.

ALBEVERIO, S.; JENTSCH, V.; KANTZ, H. (eds.), Extreme Events in Nature and Society, Berlin – Heidelberg 2006.

DE ROOVER, R.: The Rise and Decline of the Medici Bank, 1397-1494, New York 1966.

EASLY, D.; KLEINBERG, J.: Networks, Crowds, and Markets. Reasoning about a Highly Connected World, Cambridge 2010.

EPSTEIN, St. A.: Genoa and the Genoese, 958-1528, Chapel Hill – London 1996.

EPSTEIN, St. A.: An Economic and Social History of Later Medieval Europe, 1000-1500, Cambridge 2009.

Epstein, St. R.: Freedom and Growth. The rise of states and markets in Europe, 1300–1750 (Routledge Explorations in Economic History 17), London – New York 2000.

FELLONI, G.: A profile of Genoa’s “Casa di San Giorgio” (1407-1805): a turning point in the history of credit (online: http://www.giuseppefelloni.it/rassegnastampa/A%20Profile%20of%20Genoa%27s%20Casa%20di%20San%20Giorgio.pdf) 

FELLONI, G.: Genoa and the History of Finance: a Series of Firsts? (online: http://www.giuseppefelloni.it/rassegnastampa/Genova%20e%20la%20storia%20della%20finanza.pdf) 

FELLONI, G.: The Primacy of Italian finance from the Middle Ages to early modern times (online: http://www.giuseppefelloni.it/rassegnastampa/The%20Primacy%20of%20Italian%20finance%20from%20the%20Middle%20Ages%20to%20early%20modern%20times.pdf)

FERGUSON, N.: The Ascent of Money. A Financial History of the World, London 2008.

GISCHER, H.; HERZ, B.; MENKHOFF, L.: Geld, Kredit und Banken. Eine Einführung, Berlin – Heidelberg – New York ²2005.

GOLDTHWAITE, R. A.: The Economy of Renaissance Florence, Baltimore 2009.

HERLIHY, D.: Tuscans and their Families: A Study of the Florentine Catasto of 1427, New Haven – London 1985.

HUNT, E. S.: The Medieval Super-Companies. A Study of the Peruzzi Company of Florence, Cambridge 1994.

HUNT, E. S.; MURRAY, J. M.: A History of Business in Medieval Europe, 1200-1500, Cambridge 1999.

KANTZ, H.; SCHREIBER, Th.: Nonlinear Time Series Analysis. Cambridge ²2004.

KEDAR, B.: Merchants in Crisis, New Haven, CT 1976.

LANE, F. C.: Venice. A Maritime Republic, Baltimore 1973.

MILLER, H.; PAGE, S. E.: Complex Adaptive Systems. An Introduction to Computational Models of Social Life (Princeton Studies in Complexity), Princeton 2007.

MUELLER, R. C.: The Venetian Money Market. Banks, Panics, and the Public Debt, 1200-1500, Baltimore 1997.

NAJEMY, J. M.: A History of Florence, 1200-1575, Chichester 2006.

ORIGO, I.: “Im Namen Gottes und des Geschäfts”. Lebensbild eines toskanischen Kaufmanns der Frührenaissance, Munich 1985.

PADGETT, J. F.; MCLEAN, P. D.: Economic Credit in Renaissance Florence, The Journal of Modern History, Vol. 83, No. 1 (March 2011), pp. 1-47.

PEZZOLO, L.: Government Debts and Credit Markets in Renaissance Italy (Working Paper, Department of Economics, Ca’ Foscari University of Venice), Venice 2007.

PEZZOLO, L.: The Rise and Decline of a Great Power: Venice 1250-1650 (Working Paper, Department of Economics, Ca’ Foscari University of Venice), Venice 2006.

PREISER-KAPELLER, J.: (Not so) Distant Mirrors: a complex macro-comparison of polities and political, economic and religious systems in the crisis of the 14th century. International Conference “The Angevin Dynasty (14th Century)” in Targoviste (Romania), October 21st-23rd 2011 (Working Paper online: http://oeaw.academia.edu/JohannesPreiserKapeller/Papers).

PREISER-KAPELLER, J.: A complex systems approach to the evolutionary dynamics of human history: the case of the Late Medieval World Crisis. Symposium “Evolution throughout the Sciences and Humanities”. Vienna 2012 (Working Paper online: http://oeaw.academia.edu/JohannesPreiserKapeller/Papers)

PREISER-KAPELLER, J.: Complex historical dynamics of crisis: the case of Byzantium, in: S. JALKOTZY-DEGER – A. SUPPAN (eds.), Krise und Transformation. Vienna 2012, 69–127.

REINHART, C. M.; ROGOFF, K. S.: This Time is different. Eight Centuries of Financial Folly, Princeton – Oxford 2009.

SCHEFFER, M.: Critical Transitions in Nature and Society (Princeton Studies in Complexity), Princeton 2009.

SINHA, S.; CHATTERJEE, A.;  CHAKRABORTI, A.; CHAKRABARTI, B. K.: Econophysics. An Introduction, Weinheim 2011

SORNETTE, D.: Why Stock Markets Crash. Critical Events in Complex Financial Systems, Princeton – Oxford 2003.

STASAVAGE, D.: States of Credit. Size, Power, and the Development of European Polities, Princeton – Oxford 2011.

STAHL, A. M.: Zecca. The Mint of Venice in the Middle Ages, Baltimore – London 2000.

TALEB, N. N.: The Black Swan. The Impact of the Highly Improbable, London – New York 2008.

THOME, H.: Zeitreihenanalyse. Eine Einführung für Sozialwissenschaftler und Historiker, Munich – Vienna 2005.

VALÍČKOVÁ, P.:  Janovská banka San Giorgio: Příspěvek k dějinám veřejného dluhu (“San Giorgio: lessons from a history of public debts”), Brno 2010.

WILKINSON, N.: An Introduction to Behavioral Economics, Houndsmill – New York 2008.

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The Complex Mediterranean

Presentation on video: "The Complex Mediterranean. Networks, diffusion and social dynamics in the pre-modern period"

www.youtube.com/watch?v=5IiMfnagwno&index=2&list=PLxGU2gDyMnMkjcwWCpwr7-oPLn9rDtgOE

Keynote lecture by Johannes Preiser-Kapeller, given at the Workshop: “Bridging the Gaps: (Ancient) History from the Perspective of Mathematical and Computational Modelling and Network Analysis” (Brno, CZ, November 2015: http://gehir.phil.muni.cz/)

Abstract: “The Complex Mediterranean. Networks, diffusion and social dynamics in the pre-modern period”

Johannes Preiser-Kapeller, Institute for Medieval Research, Division of Byzantine Research, Austrian Academy of Sciences

Email: Johannes.Preiser-Kapeller@oeaw.ac.at

Website: http://oeaw.academia.edu/JohannesPreiserKapeller

The “Mediterranean” has become one of the most prominent and most-discussed concepts in historical studies since Braudel´s masterpiece of 1949, more recently followed by studies such as Horden and Purcell´s “Corrupting Sea” (2000), Abulafia´s “Great Sea” (2011) or Broodbanks “Making of the Middle Sea” (2013). Across this scholarship, we encounter various “Mediterraneans”, sometime unified and centres of their own “world systems”, sometimes fragmented into a multitude of “micro-regions” and “micro-ecologies”. In this paper, I will demonstrate how concepts of network analysis and complexity theory can contribute to an integration of these various facets of the “Middle Sea” and a better understanding of the dynamics of its integration and dis-integration during time. Furthermore, phenomena of (cultural, religious, economic or epidemic) diffusion will be discussed against this changing framework and in their interplay with “global”, regional and local networks. In general, the aim is to highlight aspects of social complexity of Mediterranean history beyond metaphors.

 

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Climate, Crusades and Collapse?

Upcoming Lecture: Climate, Crusades and Collapse? The Eastern Mediterranean ca. 1000-1200 (Princeton University, April 6th)

http://climatechangeandhistory.princeton.edu/events/climate-crusades-and-collapse-eastern-mediterranean-ca-1000-1200

Princeton University, April 6, 2016 - 4:30pm

Location: Dickinson 211

Speaker: Johannes Preiser-Kapeller, Austrian Academy of Sciences, Institute for Medieval Research, Division of Byzantine Research

This lecture discusses a recently proposed scenario of a climate-induced “Collapse of the Eastern Mediterranean” in the 11th century AD. It demonstrates that such a scenario cannot be maintained when confronted with proxy data from various regions. On the other hand, data on the interplay between environment and economy in the Komnenian period (1081–1185) and evidence for a change of climatic conditions in the period of the Angeloi (1185–1204) is presented, arguing that climatic parameters should be taken into consideration when comparing socio-economic dynamics in the Eastern Mediterranean with those in Western Europe. The necessity of further research on the regional as well as over-regional level for many aspects of the interaction between human society and environment in the medieval Eastern Mediterranean is highlighted.

See also the forthcoming paper:  J. Preiser-Kapeller, A Collapse of the Eastern Mediterranean? New results and theories on the interplay between climate and societies in Byzantium and the Near East, ca. 1000–1200 AD, Jahrbuch der Österreichischen Byzantinistik 65 (2015) 195-242 (https://www.academia.edu/19734639/A_Collapse_of_the_Eastern_Mediterranean_New_results_and_theories_on_the_interplay_between_climate_and_societies_in_Byzantium_and_the_Near_East_ca._1000_1200_AD

Fig.: Reconstruction of climatic conditions and general trends in agricultural production in the Byzantine Empire in the 11th cent. AD

 

The lecture is organised within the framework of the Climate Change and History Initiative

(http://climatechangeandhistory.princeton.edu/):

It follows a comparative approach to climate, environment and society in Eurasia, towards understanding the impact of climate on complex societies. This interdisciplinary project will investigate the impact of climatic changes across the last two millennia on societies in two environmentally sensitive areas:

  • The eastern Mediterranean basin (including the Balkans, Anatolia and the Near and Middle East).
  • The eastern Eurasian steppe, in particular Mongolia and the regions north of China.

The main foci of the project are (1) the differential impacts of climate and environmental change on society and state formation and (2) the impact of human society and polities on the environment.

From Austria, members of the team are Mihailo Popović and Johannes Preiser-Kapeller (both OEAW/IMAFO-ABF) (http://climatechangeandhistory.princeton.edu/about/people)

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The Deluge of 628 AD and the Collapse of Ancient Iraq

In a most recent article, a team of climatologists and historians around Ulf Büntgen has proposed the identification of a “Late Antique Little Ice Age” in the period from 536 to 660 AD which was characterised by significant socio-political upheavals and catastrophes such as volcanic eruptions and plague epidemics. Among the extreme events not included into their scenario by Büntgen et alii is the severe flood which in 628 AD affected what is now modern-day Southern Iraq, then the core province of the mighty Sasanian Empire, which was not to survive the following decades.

by Johannes Preiser-Kapeller, OEAW (Johannes.Preiser-Kapeller@oeaw.ac.at)

In his “Book of the Conquests of Lands”, the 9th century Arab historian al-Balādhurī reported: “(…) in the year 7 or 6 of Hegira [628/629] the Euphrates and the Tigris had a considerable flood, such as had never been seen before or after: large breaches opened that [the Sasanian Great King] Khusro [II] Parvez tried to close, but the water was stronger and reached the low country, submerging villages and crops and several land districts in this place. Khusro [II Parvez] came to the site in person to block the breaches: he laid a pile of silver on a leather tablecloth and put to death those workers who did not work hard enough (it is said that on a single dike he put under the cross, in one day, forty of those who worked there), but he could not stop the water. At the same time, the Arabs invaded Iraq and the Persians became henceforth preoccupied by war, to the point that the breaches grew larger without anyone worrying about it: the landowners in the villages were powerless to block them, so large were they, so the marshes grew in extent.” Al-Baladhuri X: 453-454 (transl. Hitti)

Great King Khusro II, called Parvez (“The Victorious”) at that time had ruled over the Sasanian Empire, which in its core encompassed modern-day Iran and Iraq, for almost 40 years (since 590 AD). Most of this time, he had waged war against the neighbouring Eastern Roman Empire. Since 602 and especially after 610 AD, Sasanian armies had occupied the richest provinces of their traditional imperial rival in Syria, Palestine and Egypt; two years before the flood of the Tigris, Persian troops even had stood at the Asian side of the Bosporus vis-à-vis the Roman capital of Constantinople. Yet in the face of the natural disaster, the Great King seemed almost as helpless as a mere mortal. 

Fig.: Taq-e Bostan in Iran: relief of Great King Khusro II in the centre with the goddess Anahita to the left and the god Ahura Mazda to the right.

In the narrative of al-Balādhurī and other Arab historians, the incipient invasion of the troops of the newly emerging Arab umma of Islam added up to the crisis of the Sasanian Empire and hindered the Persians to take successful measures against the flooding. But as a matter of fact, the Arab invasion started in earnest only four years later in 632. More probably, it was a turning of tides in the war with Rome which impeded a more effective handling of the disaster. Since 622 AD, the Roman Emperor Heraclius (r. 610-641) had been able to perturb the not yet consolidated rule of the Persians over Eastern Anatolia and the Caucasus region in a series of audacious campaigns. In Armenia and Georgia, he found valuable new clients. Furthermore, the Emperor allied himself with the Khanate of Western Turks, who controlled the Steppes to the north of the Caucasus and Iran in Central Asia. In 627, Turkish horsemen devastated the border provinces of the ancient Sasanian realm while Heraclius defeated a Persian army at Niniveh in Northern Iraq and marched towards the residence of Khusro II in Dastagird near the capital of Ctesiphon (near modern-day Baghdad), to which the Great King had to flee.

Fig: Late Antique Mesopotamia and the approx. area affected by the flood of 628 AD to the south of Wāsit; places in brackets were founded later under Arab rule  (map: J. Preiser-Kapeller, 2016).

In this most critical situation, disaster struck. The short and long term impacts of the flood of 628 AD are described in the work of the Persian geographer Ibn Rusta of the 10th century: “The river cut through the earth until it started flowing past Wāsit and its waters flowed into al-Batā´ih [the marshes]. At that time [before the flood], al-Batā´ih were cultivated lands that continued without interruption up to the land of the Arabs (…) and (…) up to the land of Maisān. The water took possession of the low-lying areas, and the higher areas became islands. These places are known to this day in al-Batā´ih (…). Ruins are still visible under water in the al-Batā´ih depression, because the water is motionless and clear; this demonstrates the area used to be [solid] land. And the original marshes in which the Tigris water gathered, before it shifted to the area of Wāsit, were in Jūhā, in the area between al-Madār and Abdasī; when the Tigris shifted, the water was cut off from these marshes, and they became desolate deserts. Whoever passes through them in summer, suffers fierce sand storms.” (transl. Verkinderen 2015, 54).

Fig.: A street in Baghdad after a flood in October 2015.

The disaster thus affected the region not only on a short term basis, but permanently and significantly modified the landscape; a vast area to the south of the town of Wāsit became known as al-Batā´ih (the marshes) for centuries. Wide areas of cultivated land were lost, settlements disappeared and people had to leave their homes. In his magisterial new study on the waterways of Iran and Iraq in the early Islamic period, Peter Verkinderen describes the hydrological background to this catastrophe: “(…) both Tigris and Euphrates breached their banks at numerous places in 628. (…) Like the Euphrates – and many other meandering rivers – the Tigris regularly breached its bank in its lower reaches, and over the course of centuries created levees, raised riverbeds that rise up to several metres above the plain. A breach (or crevasse) occurs when part of this raised bank of the river collapses, usually during high water periods. The force of the water rapidly widens the gap, but because the river is located above the level of the surrounding plain, the water also starts to erode the levee in a vertical direction, cutting a channel through the sides of the levee that is lower than the original riverbed; at worst, the river can abandon its bed entirely (avulsion). The results of such a breach are dramatic: it becomes next to impossible to make the river return to its former – raised – bed, and the river inundates a large area at the side of the levee where the breach occurred; depressions can be turned into lakes or marches. (…) Moreover, the levee of the former bed becomes a dike that prevents the water from reaching the area at the other side of the levee. In a worst-case scenario, a breach permanently inundates the fertile areas one side of the levee, and entirely deprives the area on the other side of the levee from water. This appears to be exactly what happened with the Tigris.” (Verkinderen 2015, 54).

Fig.: The marshes in the delta region of Euphrates and Tigris today

The hydrological causes for this disaster can be found in the climatic conditions of the “Late Antique Little Ice Age“ as recently identified by Ulf Büntgen and his colleagues: various sources document a series of extremely cold and snow-rich winters in the regions of the waterheads of Euphrates and Tigris and their tributaries in Eastern Anatolia, Armenia and the Zagros mountains in the years 623 to 628 AD (cf. for instance Telelis 2004; Haldon 2014). While these harsh weather conditions allowed the Roman army to outmanoeuvre their Persian foes in the Transcaucasian areas, the abundance of melt water resulted in the catastrophic floods of the Euphrates and the Tigris. But as Peter Christensen has outlined in his now classic volume on the “Decline of Iranshahr” (1993), disaster in 627/628 AD struck the Persian provinces at the same time also as another wave of the so-called Justinianic plague, which time and again reduced populations across the Mediterranean and the Near East since the 540s (the reign of Emperor Justinian I). The losses of populations due to the epidemic and of productive land due to the flood further destabilised the Sasanian polity already on the verge of defeat from the hand of the Romans; according to the estimates of Christensen, the area of Iraq contributed 50 % of the Empire´s revenues – and half of these may have been lost due to the deluge of 628 AD.

Fig: The trajectories of temperature and the series of political upheavals in the “Late Antique Little Ice Age” between 536 and 660 AD as reconstructed by Büntgen et al. 2016

 

The most prominent victim of this combination of military and natural disasters became Great King Khusro II himself: in February 628, he was deposed by leading members of the aristocracy and later killed in prison. He was replaced by his son Kavadh II Siroe, who was able to negotiate peace with Emperor Heraclius, but died under unclear circumstances already in September 628. The regime now ran out of the rudder: in the following four years, not less than seven kings and queens succeeded to the Sasanian throne before Yazdegerd III (r. 632-651) established a longer lasting rule again. But he was the last of the Persian Great Kings and lost his crumbling empire to the Arabs, who first conquered Iraq and then entire Iran.

The Sasanian Empire had come to an end after more than 400 years. The flood of 628 AD of course was not the sole trigger of its demise. Already the rule of Khusro II in 590 AD had started with civil war and internal unrest; as Parvaneh Pourshariati has demonstrated in her monograph of 2008, the socio-political framework of Sasanian power as such was less centralised and stable as hitherto assumed. But the series of climate-induced disasters (weather extremes, epidemics and flood) together with the devastating war with the Romans and later the Arabs in the 620s-640s definitely tested the Persia´s resilience beyond its limits (as they almost did also for the Eastern Roman Empire). The Sasanian Empire thus may be added to the “victims” of the “Late Antique Little Ice Age”.

Selected Bibliography:

J. L. Brooke, Climate Change and the Course of Global History. A rough Journey, Cambridge 2014.

U. Büntgen et al., Cooling and societal change during the Late Antique Little Ice Age from 536 to around 660 AD, Nature Geoscience, published online 8 February 2016: http://dx.doi.org/10.1038/ngeo2652 (with supplementary material)

P. Christensen, The Decline of Iranshahr: Irrigation and Environments in the History of the Middle East, 500 B.C. to A.D.1500, Copenhagen 1993.

M. Djamali et al., A late Holocene pollen record from Lake Almalou in NW Iran: evidence for changing land-use in relation to some historical events during the last 3700 years, Journal of Archaeological Science 36 (2009) 1363–1375.

J. F. Haldon et al., The Climate and Environment of Byzantine Anatolia: Integrating Science, History, and Archaeology, Journal of Interdisciplinary History 45,2 (2014) 113–161.

W. V. Harris (ed.), The Ancient Mediterranean Environment between Science and History (Columbia Studies in Classical Tradition 39), Leiden – Boston 2013.

J. Howard-Johnston, Witnesses to a World Crisis. Historians and Histories of the Middle East in the Seventh Century, Oxford 2010.

A. Izdebski – J. Pickett – N. Roberts – T. Waliszewski, The environmental, archaeological and historical evidence for regional climatic changes and their societal impacts in the Eastern Mediterranean in Late Antiquity. Quaternary Science Reviews: http://dx.doi.org/10.1016/j.quascirev.2015.07.022

L. K. Little (ed.), Plague and the End of Antiquity: The Pandemic of 541–750, Cambridge 2006.

J. Luterbacher et al., A Review of 2000 Years of Paleoclimatic Evidence in the Mediterranean, in: The Climate of the Mediterranean region: from the past to the future, ed. P. Lionello, Amsterdam 2012, 87–185.

M. McCormick u. a., Climate Change during and after the Roman Empire: Reconstructing the Past from Scientific and Historical Evidence, Journal of Interdisciplinary History 43, 2 (2012), 169–220.

A. Naderi Beni et al., Caspian sea-level changes during the last millennium: historical and geological evidence from the south Caspian Sea, Climate of the Past 9 (2013) 1645–1665.

W. Nützel, Einführung in die Geo-Archäologie des Vorderen Orients, Wiesbaden 2004.

P. Pourshariati, Decline and Fall of the Sasanian Empire. The Sasanian-Parthian Confederacy and the Arab Conquest of Iran, New York 2008.

J. Preiser-Kapeller, A Collapse of the Eastern Mediterranean? New results and theories on the interplay between climate and societies in Byzantium and the Near East, ca. 1000–1200 AD, Jahrbuch der Österreichischen Byzantinistik 65 (2015) 195-242.

F. Rahimi-Laridjani, Die Entwicklung der Bewässerungslandwirtschaft im Iran bis in sasanidisch-frühislamische Zeit, Wiesbaden 1988.

D. Stathakopoulos, Famine and Pestilence in the Late Roman and Early Byzantine Empire, Aldershot 2004.

I. G. Telelis, Climatic Fluctuations in the Eastern Mediterranean and the Middle East AD 300–1500 from Byzantine Documentary and Proxy Physical Paleoclimatic Evidence – a Comparison, Jahrbuch der Österreichischen Byzantinistik 58 (2008), 167-207.

I. G. Telelis, Meteorologika phainomena kai klima sto Byzantio, 2 Vol.s, Athens 2004.

P. Verkinderen, Waterways of Iraq and Iran in the Early Islamic Period. Changing Rivers and Landscapes of the Mesopotamian Plain, London – New York 2015.

P.-L. Viollet, Water Engineering in Ancient Civilizations. 5,000 Years of History, Boca Raton 2007.

J. Wiesehöfer, Das antike Persien. Von 550 v. Chr. bis 650 n. Chr., Zürich 1993.

 

 

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Exploring the spatial network of Late Byzantine history

An interactive map of 336 localities connected through the mobility of 2402 members of the Byzantine elite in the years 1282 to 1402

https://www.google.com/maps/d/edit?mid=zFF_0-ggg3xI.kzPtUQfs7H8s&usp=sharing

I have created a database of more than 2400 individuals and 330 places (on the basis of the Prosopographisches Lexikon der Palaiologenzeit, augmented with additional data) and a network model of these places connected due to the mobility of people in the years 1282 to 1402 CE. You can now explore this network online if you follow the link above. One can also only look at the distribution of places by unselecting the network layer. More sophisticated interactive visualisations of the data are under construction, but this site provides a first impression of the density and amount of connections of Late Byzantium.

More information on the underlying database you can find here: http://www.academia.edu/8247283/A_new_view_on_a_century_of_Byzantine_history_The_Vienna_Network_Model_of_the_Byzantine_Elite_1282-1402

The database is part of the project "Mapping Medieval Conflicts" (http://oeaw.academia.edu/MappingMedievalConflict)

More on this project and the underlying methodology you can also learn here: https://www.academia.edu/19333312/Calculating_the_Middle_Ages_The_project_Complexities_and_networks_in_the_Medieval_Mediterranean_and_Near_East_COMMED_

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The Seshat: Global History Databank-Project

A team of scholars from around the world, from fields as diverse as evolutionary biology, psychology, and archaeology, is working on a project that's concentrating huge volumes of data on social complexity, warfare, ritual, religion, resources, politics, and economics all into one place.

The Databank systematically collects what is currently known about the social and political organization of human societies and how civilizations have evolved over time; https://evolution-institute.org/project/seshat/

This massive collection of historical information allows  to rigorously test different hypotheses about the rise and fall of large-scale societies across the globe and human history. Working with a large international and interdisciplinary team, our database offers the means to study the past through well-established scientific techniques.

The founding editor and overall coordinator of Seshat is Professor Peter Turchin (UConn), an evolutionary biologist and theoretician of human history (Cliodynamics; http://peterturchin.com/); currently, Prof. Turchin is guest of the University of Vienna for the conference "The Haves and the Have-Nots: Exploring the Global History of Wealth and Income Inequality" (http://altegeschichte.univie.ac.at/fileadmin/user_upload/inst_alt_ges_altertum_papyr/Veranstaltungen/Einladung_the_haves_and_the_have_nots_web.pdf).

Seshat and Prof. Turchin are also cooperating with Johannes Preiser-Kapeller, who is responsible for the data on Byzantium for the Seshat-project and himself is executing several projects on complexity theory, network analysis and history (http://oeaw.academia.edu/JohannesPreiserKapeller).

You can also learn more about this project by watching this video:

www.youtube.com/watch?v=T1l5Mr2xEPg

 

 

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Emperor of Byzantium: a lifetime position?

Basileus ton Rhomaion – “Emperor of the Romans”: sounds like a position of power and glory. Yet recent studies (by Ralph-Johannes Lilie or Anthony Kaldellis, for instance) have highlighted the instability and vicissitudes of imperial rule in Byzantium. Therefore (inspired also by Lilie), we made a new statistical analysis of the dynamics of the imperial regime. What were the chances for an emperor to stay in power for a longer period?

Assume that you are a Venetian banker asked by the Emperor in Constantinople for a loan which he promises to pay back over the next 20 years of his reign. Understandably, you would like to know the probability that your potential debtor will be actually able to do so – and to estimate the risk of an earlier change of ruler who may declare the obligations of his precursor null and void. To anticipate the results of our calculations: the chances that your client will make it the entire 20 years are bad.

We based our calculations on all rules in the Byzantine Empire for the period between the death of Emperor Constantine the Great (337 CE) and the Fall of Constantinople to the Ottomans (1453 CE); for the time of Latin rule in Constantinople between 1204 and 1261 CE, we used the data for the Emperors of Nicaea. Furthermore, we differentiated between rules with a non-violent and a violent start (the use of force to re-place the former emperor). You can find an overview of statistical results below.

Fig.: Statistical properties of the distribution of the durations of rules in the Byzantine Empire, 337-1453 CE (J. Preiser-Kapeller, 2015)

 

Although the mean duration of rules is more than 12 years, the lengths of reigns are distributed very unequally; 25 % of all emperors made it not beyond their third year, for instance. On the other hand, only 25 % ruled beyond their 19th year. A visualisation of the frequency distribution of rule durations makes these inequalities even more visible (see below); in contrast to an equal, so-called “normal distribution” (the red line), we observe a multitude of reigns below the mean of 12 years and a “long tail” of some few longer lasting rules.

Fig: The distribution of frequencies of durations of rules in the Byzantine Empire, 337-1453 CE (J. Preiser-Kapeller, 2015)

 

But as the data above indicated, chances for a long reign were even smaller if you started your rule with violence; in this case, the mean duration of rules is only ca. 10 years, and 25 % of emperors did not make it beyond their second year. These differences between rules with violent and non-violent starts become also visible in a so-called “survivorship-plot” (see below): the red line indicates the durations of all rules, the blue line of those with non-violent starts and the green line of those with violent starts. Clearly, we observe a divergence of survival chances between non-violent and violent rules after the seventh year (a “Seven Year Itch” for usurpers?) and a more rapidly declining rate of survival for violent rules afterwards.

Fig.: “Survivorship”-plot of all reigns (“total”), reigns initiated by violence (“violent”) and not initiated by violence (“non-violent”) for Byzantium, 337-1453 CE; the lines indicate the (declining) number of reigns which lasted up to that number of years, starting from 0 years.

 

You as Venetian investor therefore should keep in mind that your potential client has a 30 % chance to make it to his 20th year of reign if he has started his rule without violence – but only a 19 % chance if he did so.

The occurrence of ruler change and especially violent ruler change was of course not equally distributed across the Byzantine centuries; as every student of Byzantine history knows, there were periods of crisis and internal turmoil when emperors were replacing each other very quickly year after year. The graphs beyond illustrate this chronological distribution for all changes of rulers and for violent ruler changes.

Fig. Years of ruler change per decade in the Byzantine Empire, 337-1453 CE (J. Preiser-Kapeller, 2015)

 

Fig. Years of violent ruler change per decade in the Byzantine Empire, 337-1453 CE (J. Preiser-Kapeller, 2015)

 

Furthermore, in an earlier paper (http://www.academia.edu/3255595/Games_of_Thrones._The_temporal_dynamics_of_ruler_change_in_the_Roman_and_Post-Roman_World_0-800_CE_; in this paper you also find more technical background on our calcuations) we have compared the dynamics of ruler change in Byzantium with other polities across Eurasia for the early medieval period – and in some neighbouring polities, chances for a long reign were even smaller (only 25 % of all Caliphs made it beyond their 12th year, for instance). You as an investor therefore should be aware that a bet on a long rule of your royal debtor would have been a risky speculation in almost any case.

Fig: A violent start for a (relatively long-lasting) rule: the murder of Emperor Michael III by Basil the Macedonian, 867 CE (Skylitzes Matritensis)

Johannes Preiser-Kapeller, ÖAW – RGZM

Literature:

Allison, P. D.: Event History Analysis: Regression for Longitudinal Event Data (Quantitative Applications in the Social Sciences). Sage, London 1984.

Berg-Schlosser, D./Cronqvist, L.: Aktuelle Methoden der Vergleichenden Politikwissenschaft. Einführung in konfigurationelle (QCA) und makro-quantitative Verfahren. Opladen & Farmington Hills 2012.

Blaydes, L./Chaney, E.: The Feudal Revolution and Europe’s Rise: Political Divergence of the Christian West and the Muslim World before 1500 CE. American Political Science Review, February 2013, 1-19 (doi:10.1017/S0003055412000561).

Box-Steffensmeier, J. M./Jones, B. S.: Event History Modeling. A Guide for Social Scientists. Cambridge 2004.

Eder, W./Renger, J. (eds.): Herrscherchronologien der antiken Welt. Namen, Daten, Dynastien (Der Neue Pauly Supplemente 1). Stuttgart – Weimar 2004.

Kaldellis, A.: The Byzantine Republic People and Power in New Rome. Cambridge, Mass. 2015.

Kantz, H.; Schreiber, Th.: Nonlinear Time Series Analysis. Cambridge ²2004.

Kokkonen, A./Sundell, A.: Delivering Stability - Primogeniture and Autocratic Survival in European Monarchies 1000-1800. QoG Working Paper Series 2012:3, Department of Political Science, University of Gothenburg April 2012.

Lilie, R.-J.: Der Kaiser in der Statistik. Subversive Gedanken zur angeblichen Allmacht der byzantinischen Kaiser, in: Ch. Stavrakos – A. Wassiliou-Seibt et al. (eds.), Hypermachos: Studien zur Byzantinistik, Armenologie und Georgistik ; Festschrift für Werner Seibt zum 65. Geburtstag. Wiesbaden 2008, 211-234.

Preiser-Kapeller, J.: Complex historical dynamics of crisis: the case of Byzantium, in: S. Jalkotzy-Deger – A. Suppan (eds.), Krise und Transformation. Vienna 2012, 69–127.

Preiser-Kapeller, J.: Games of Thrones. The temporal dynamics of ruler change in the Roman and Post-Roman World (0-800 CE), Working Paper: http://www.academia.edu/3255595/Games_of_Thrones._The_temporal_dynamics_of_ruler_change_in_the_Roman_and_Post-Roman_World_0-800_CE_

Thome, H.: Zeitreihenanalyse. Eine Einführung für Sozialwissenschaftler und Historiker, Munich – Vienna 2005.

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Wie komplex war die Wirtschaft des Römischen Reiches?

Die wirtschaftlichen Turbulenzen, die Europa und die Welt seit 2008 heimsuchen, haben u. a. gezeigt, dass die auf vereinfachenden, „linearen“ Modellen basierenden Theorien der klassischen Wirtschaftswissenschaften der tatsächlichen Komplexität ökonomischer Systeme nicht entsprechen. „Complexity economics“ bezieht hingegen diese Phänomene von Beginn an in ihrer Überlegungen mit ein. Doch ist ökonomische Komplexität ein Charakteristikum der modernen Wirtschaft oder kennzeichnete sie auch die Ökonomien der Vergangenheit wie etwa des Römischen Reichs? Dieser Frage gehen Historiker, Archäologen und Mathematiker im September 2015 in einem Workshop in Sagalassos (Türkei) nach.

Unter dem Titel „Complexity: a new framework to interpret ancient economic proxy data“ versammeln Jeroen Poblome (Universität Leuven, Belgien) und Koen Verboven (Universität Gent, Belgien) vom 11. bis 12. September 2015 eine Reihe von Experten aus mehreren Ländern, um der „Dynamik ökonomischer Systeme im Imperium Romanum“ auf den Grund zu gehen (http://www.rsrc.ugent.be/sdep/complexity).

Der Ort der Tagung selbst, die Ruinenstätte von Sagalassos, ca. 100 km nördlich von Antalya und seit 1991 von belgischen Archäologen systematisch erforscht, ist ein beeindruckendes Monument dieser Dynamik: die Stadt wurde unter römischer Herrschaft zu einem wichtigen Zentrum der Provinz Pisidien und florierte bis ins 6. Jh., wie die Pracht der Überreste der öffentlichen Bauten wie etwa des Theaters demonstriert. Ab der Mitte des 6. Jh.s verfiel die Stadt aber (wie viele andere Zentren Kleinasiens in dieser Zeit) und wurde im späteren 7. Jh. verlassen, ohne jemals wieder in großem Umfang besiedelt worden zu sein. Als mögliche Ursachen werden die ab 542 in Wellen wiederkehrende Pest, Klimawandel und feindliche Invasionen (im 7. Jh. zuerst die Perser, danach die Araber) bzw. eine Kombination dieser Faktoren genannt (http://www.sagalassos.be/).

Abb.: Das römische Theater von Sagalassos (Pisidien/heute Türkei)

 

“Complexity economics”, ein Anwendungsbereich der Komplexitätswissenschaften, der insbesondere ab den 1990er Jahren aufblühte, geht, wie W. Brian Arthur, eine der Pioniere dieser Wissenschaft ausführt, von „der Annahme aus, dass Wirtschaft sich nicht notwendigerweise im Gleichgewicht befindet: wirtschaftliche Akteure (Firmen, Konsumenten, Investoren) verändern ständig ihre Aktionen und Strategien in Reaktion auf die Resultate, die sie im Wechselspiel miteinander erzeugen. (…) Komplexitätsökonomik sieht die Wirtschaft also in Bewegung, sich ständig selbst „berechnend“, sich ständig neu konstruierend. Während die Gleichgewichtsökonomik Ordnung, Determinanz, Deduktion und Stasis betont, betont die Komplexitätsökonomik Kontingenz, Indeterminanz, Sinn-Stiftung und Offenheit für Veränderung“. (W. B. Arthur, Complexity and the Economy. Oxford 2015, 1). Das wechselhafte Schicksal großer Siedlungen wie Sagalassos scheint auf vergleichbare komplexe Dynamiken der römischen Wirtschaft hinzudeuten.

Abb.: Die Wirtschaft des Römischen Reichs im Prinzipat (1.-3. Jh. n. Chr.) (von: agiw.fak1.tu-berlin.de)

 

Tatsächlich besteht aber kein Konsens über wesentliche Merkmale einer Komplexität der Wirtschaft des Imperium Romanum. Eine intensive Debatte kreist um den Grad der wirtschaftlichen Integration innerhalb des Römischen Reiches: war es eine „enorme Ansammlung wechselseitig abhängiger Märkte“, deren wirtschaftliche Verflechtung auch in einer Interdependenz der Preisentwicklung in verschiedenen Regionen resultierte (so Peter Temin)? Oder müssen wir annehmen, das „Konnektivität und Isolation sehr ungleich“ über eine tatsächlich fragmentiere Mittelmeerwelt verteilt waren, innerhalb der sich nur einige wenige Inseln integrierter Märkte befanden (so Paul Erdkamp oder Peter Fibinger Bang). Eine andere Diskussion konzentriert sich auf die Rolle und den Anteil des Staates in und an der Wirtschaft: war das Römische Reich ein „tributbasiertes Imperium“, dessen Transfer von Gütern für die Armee oder die Versorgung der imperialen Hauptstädte den vorherrschenden (oder sogar einzigen) Sektor von Handel im großen Umfang darstellte? Bestimmten die Bedürfnisse und die Logistik des Imperiums zumindest in einem hohen Masse Orientierung und Bedeutung der Achsen der überregionalen Verteilung sowohl für den staatlichen als auch den privaten Sektor? Oder unterliegen wir einer „Überschätzung des staatlich kontrollierten Sektors der Wirtschaft“ (so Jean-Michel Carrié), die uns zu der “unangemessenen und unrealistischen Idee” verleitet “dass die imperiale Wirtschaft durch ein große Verteilungssystem kontrolliert war" (so Peter Fibinger Bang)?

Abb.: Eine komplexe integrierte römische Marktwirtschaft hätte auch manche unerwartete Probleme mit sich gebracht (aus: Asterix-Band Nr. 23: "Obelix GmbH & Co.KG")

 

Wiewohl der staatliche Sektor der Wirtschaft in unseren Quellen sicher überrepräsentiert ist, so bieten uns diese Texte zumindest Grundlagen für Überlegungen zum (minimal notwendigen) Umfang und Grad der organisatorischen Komplexität, um den “Fluss an Ressourcen und Bevölkerung” aufrechtzuerhalten, auf den das Reich für sein Überleben angewiesen war (Sam White nennt dies “imperiale Ökologie”). Ebenso „rehabilitieren“ jüngste Debatten in der Wirtschaftsgeschichte die Bedeutung des Staates für die Entwicklung einer Wirtschaft; P. Vries etwa bezeichnet staatliche Aktivität als „nicht ausreichende, (…) aber notwendige Bedingung“ für das wirtschaftliche Wachstum vor-moderner Wirtschaften. Der Zusammenbruch des (West)Römischen Reiches im 5. Jh. bietet auch argumenta ex negativo für die Bedeutung des imperialen Rahmens für die ökonomische Komplexität bzw. ihrer Entwicklung in Abwesenheit dieses Rahmens. Eines der bemerkenswertesten Charakteristika der römischen Wirtschaft war die weitreichende Verbreitung von Gütern (insbesondere belegt durch Keramikfunde), „nicht nur geographisch (über hunderte von Meilen), aber auch sozial (sodass sie nicht nur die Reichen, sondern auch die Armen erreichte“, wie Bryan Ward-Perkins darlegt.

Abb.: Schätzung der Entwicklung wirtschaftlicher Komplexität in verschiedenen Regionen der (post)römischen Welt, aus: B. Ward-Perkins, The Fall of Rome and the End of Civilization. Oxford 2005.

 

Ward-Perkins stellt auch fest, dass der Zusammenbruch des Imperium Romanum in Westeuropa mit einem „Ende dieser Komplexität“ einherging, sodass sogar „an den wenigen Orten, wie etwa Rom, wo die Produktion und Importe von Keramik immer noch außergewöhnlich reichhaltig blieben, das mittlere und untere Marktsegment für Qualitätsgüter vollkommen verschwand.“ Eine solche Interpretation des Endes des römischen Wirtschaftssystems impliziert wiederum einen beachtlichen Grad an Interdependenz in den vorangehenden Jahrhunderten, denn ansonsten hätte sein Zusammenbruch selbst relativ periphere Gebiete wie das römische Britannien nicht in einem solch dramatischen Ausmaß beeinflusst. Vielmehr wäre nach dem Verschwinden des übergreifenden imperialen Rahmens eine Ansammlung „isolierter“, vielleicht „autarker“ Cluster von Siedlungen oder Regionen (wieder) sichtbar geworden, deren (dann nur marginal reduzierter) Wohlstand so wie zuvor hauptsächlich auf ihrer internen sozio-ökonomischen Dynamik basiert hätte. Dies war aber offensichtlich nicht der Fall, und die Fragmente des früheren Systems waren alleine weniger als ihre Summe (wie man es für ein komplexes System erwarten würde).

Abb.: Das Römische Reich als Netzwerk der Interaktion zwischen Siedlungen (weiß) und der mögliche Zerfall in regionale Cluster (gelb) entlang strukturell angelegter Bruchlinien (Netzwerkmodell und Grafik: J. Preiser-Kapeller, 2014)

Diesen Fragen und möglichen Methoden und Daten zu ihre Beantwortung werden sich die Forscher in Sagalassos widmen; aus dem Workshop soll auch ein Buch hervorgehen. Die Ergebnisse werden auch für Überlegungen zur Komplexität und Dynamik moderner Wirtschaftssysteme relevant sein.

Johannes Preiser-Kapeller, ÖAW - RGZM

Literatur:

W. B. Arthur, Complexity and the Economy. Oxford 2015.

P. F. Bang, The Roman Bazaar: A Comparative Study of Trade and Markets in a Tributary Empire. Cambridge 2008.

J.-M. Carrié, Were Late Roman and Byzantine Economies Market Economies? A Comparative Look at Historiography, in: C. Morrisson (Hrsg.), Trade and Markets in Byzantium. Washington, D. C. 2012, 13-26.

P. Erdkamp, The Grain Market in the Roman Empire: A social, political and economic study. Cambridge 2005.

A. W. Mees, Die Verbreitung von Terra Sigilatta aus den Manufakturen von Arezzo, Pisa, Lyon und La Graufesenque. Mainz 2011.

J. Preiser-Kapeller, Networks as Proxies: A Relational Approach towards Economic Complexity in the Pre-Modern Period. Beitrag für den Workshop “Complexity: a new framework to interpret ancient economic proxy data”, Sagalassos, 11.-12. 9. 2015 (pre-print online: http://www.academia.edu/14599966/Networks_as_Proxies_a_relational_Approach_towards_Economic_Complexity_in_the_Pre-Modern_Period)

J. A. Tainter, The Collapse of Complex Societies (New Studies in Archaeology). Cambridge 1988

P. Temin, The Roman Market Economy. Princeton – Oxford 2013.

P. Vries, State, economy and the Great Divergence. Great Britain and China, 1680s-1850s. London u. a. 2015.

B. Ward-Perkins, The Fall of Rome and the End of Civilization. Oxford 2005.

S. White, The Climate of Rebellion in the Early Modern Ottoman Empire (Studies in Environment and History). Cambridge 2011.

 

 

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Die Physikalische Soiree: Netzwerk und Mittelalter

Ein 90minütiges Gespräch mit Lothar Bodingbauer (Ö1, freier Wissenschaftsjournalist) mit Johannes Preiser-Kapeller (ÖAW, RGZM) über Menschen, Landschaften, Netzwerke. Kommunikation, Einfluss. Veränderung.

Johannes Preiser-Kapeller untersucht mit den Mittel der Netzwerkanalyse das Beziehungsgeflecht im alten Byzanz. Im Mittelalter.

Wir sprechen über Päpste, Weihen, Beziehungen, Landschaften. Darüber, wie man ein Netzwerk darstellt und analysiert. Wir unterhalten uns über Komplexitätsforschung und über Bücher, die man mitnehmen müsste, wenn man das Büro fluchtartig verließe.

http://www.physikalischesoiree.at/archives/3205

 

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