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

Daniel, Elton L.

Most modern accounts of Middle Eastern history are constructed around the rise and fall of dynasties or states. The paradigm they employ, implicitly or explicitly, for the history of the Islamic Middle East, in particular, is familiar enough. There is the decisive watershed of the Arab conquests and the rise of Islam, followed by the golden age of the high caliphate, and then by a period of political fragmentation, decadence, and disruption of sedentary civilization culminating in the catastrophe of the Mongol invasions. This innovative and stimulating book by Peter Christensen, clearly written from the perspective of a modern "macro historian" rather than the traditional Orientalist, challenges virtually every comfortable convention of this received wisdom.

At first glance, the title of the book may seem somewhat cryptic or its subject arbitrarily defined, but it is in fact quite appropriate once one understands the author's basic assumptions and concerns as outlined in his introduction and first three chapters. The geographical focus of the book is Iran-shahr, the term which Christensen uses to refer to the area from the Euphrates to the Amu Darya. This region, which he considers a more valid unit of historical inquiry than one such as the "Middle East," gains its coherence primarily from the environmental factors of aridity and the need for extensive irrigation in agriculture rather than political and cultural elements. The theme of the book is indeed the question of the widely perceived "decline" of this region from its classical glories to the sad shadow of itself in post-Mongol times - but in a much more disciplined and precise way than one usually finds in the historical literature. Christensen does not link the concept of "decline" to the fortunes of specific states or empires in Iranshahr but to the basic and fundamental index of agricultural production, the most important economic activity in all pre-industrial societies. This relegation of political history to a subsidiary, indeed almost negligible, role explains what might otherwise seem the peculiar methodological, thematic, geographic, and chronological boundaries of Christensen's study.

Although Christensen scrutinizes a rich selection of classical and Muslim textual sources, he makes it clear that he is not interested in "philological arguments." He relies most heavily on medieval records of tax assessments, but recognizes the limited availability and questionable reliability of such reports. Along with textual sources, Christensen gives substantial weight to archaeological data and miscellaneous forms of scientific evidence. He discusses three distinct geographical components of Iranshahr - the Mesopotamian flood-plain (covered in chapters four to nine), the oases of the Iranian plateau (chapters ten to seventeen), and Sistan (chapters eighteen to twenty). He does not discuss areas such as the Caspian littoral, which he notes does not meet the environmental criteria he uses for defining Iranshahr. He begins his study in the sixth century B.C., since it was then that the whole of Iranshahr was first united under the Achaemenids, and ends it in the sixteenth century A.D., since the Ottoman conquests led to the detachment of the Mesopotamian floodplain from the rest of Iranshahr. He attempts to describe the general pattern of agricultural production for each of the three divisions of Iranshahr over this period of time, including in the process an immense amount of information about geology, hydrography, irrigation techniques, ecology and political conditions. It is difficult to summarize Christensen's conclusions without the risk of over-generalizing them, but in brief he shows that (1) the historical evolution of the Mesopotamian floodplain was fundamentally different from the two other areas of Iranshahr; (2) there was considerable local variation in economic development with some areas in "decline" well before the Mongol period and others not in "decline" until much later; and (3) when "decline" occurs it can more frequently be attributed to factors such as the environment, disease, natural disasters, localized social disorders, or mismanagement of resources than to grand political and cultural upheavals such as wars, nomadic invasions, and the increasing "bedouinization" of society. Worked into all this as a subtext is a sobering moral lesson obviously aimed at a modern audience: states should be wary of straining the environment to its limit simply to maximize the economic resources available to them, especially when the surplus revenue is intended for excessive military expenditures.

In a sense, Christensen's study is highly derivative. For example, he relies quite heavily on the work and conclusions of scholars such as R. McC. Adams, Charles Melville, and Michael Dols. It thus might not be regarded as radically new in its content. Nonetheless, Christensen has provided a great service by synthesizing numerous independent lines of research and presenting them in a way fully conversant with the techniques and concerns of contemporary historiography. Although Christensen himself does not fully explore the implications of his findings, their potential impact, especially in terms of their importance for presentations of early Islamic history, is considerable. Essentially, Christensen accepts and expands upon the idea developed in Adams' Land behind Baghdad that agricultural productivity in the Mesopotamian floodplain reached its zenith in the late Sassanian period. In the seventh century, the complex and sensitive hydraulic system built up by the Sassanians Was devastated by floods, plague pandemics, and wars which decimated the population base needed for maintaining it, and it never fully recovered. The Arab conquest was just one more factor in the "crisis of the seventh century" and probably one of less importance than disease and natural disasters. In addition, Christensen rejects A. M. Watson's notion of an Islamic "green revolution," at least in the most important part of Iranshahr. He argues that the Arabs brought no significant technological change, disseminated few if any new crops, and did little to repair the agricultural infrastructure. The caliphs, thanks to their diversion of funds to meet military expenses and their rapacious taxation policies, actually contributed to its further deterioration. From the ninth century onwards, it was in precipitous decline. For the Mesopotamian floodplain, then, the early Islamic era thus "did not usher in an era of growth and prosperity, but one of contraction and decline" (p. 73). In other parts of Iranshahr, the Sassanians also stimulated settlement and economic development, but in contrast to the Mesopotamian floodplain there was no extensive, overall crisis in the seventh century in those regions. Under local rulers and conditions, many areas continued to develop and enjoyed periods of prosperity which did not peak until the tenth or twelfth century or even later. Viewed from this perspective, it is difficult to see the Arab conquests and rise of Islam as a key event - the golden age of Iranshahr was the Sassanian period, and its silver age was not under the Abbasid caliphate but in the era of the regional dynasties.

While Christensen's approach has many virtues, it also has some conspicuous weaknesses. One is in his handling of primary sources, where he makes extensive use of translations or secondary citations without checking them against the original text or more recent editions. For example, in his discussion of Qumm he uses only Lambton's article about the Tarikh-i Qumm rather than the text itself. For the kinds of agronomical and hydrological questions at the heart of Christensen's study, the Tarikh-i Qumm is one of the most detailed and interesting sources available, and it ought to have been consulted directly - the author's professed lack of interest in problems of "transliteration" and "philological arguments" should not excuse such oversights. There are also some surprising omissions in his survey of the secondary literature. He notes the importance of the floods of 628 and bursting of the dikes along the Tigris and Euphrates, but does not mention W. Nutzel's related article on "The End of the South Mesopotamian Civilizations." He gives much emphasis to reports of plagues and epidemics, but makes no reference to L. I. Conrad's important observations on "Arabic Plague Chronologies and Treatises." He discusses questions surrounding the construction of the defensive wail in Gurgan but does not refer to M. Y. Kiani's report on "Excavations on the Defensive Wall of the Gurgan Plain." There is also minimal discussion of the literature which would help put his findings in a better comparative context - no indications of familiarity, for example, with B. Z. Kedar's work on "The Arab Conquests and Agriculture" (for a different part of the Middle East) or Joseph Tainter's highly relevant Collapse of Complex Societies (for a theoretical and global perspective). Finally, there are possible questions about the argumentation itself. Are tax revenues an index of agricultural production or simply of the ability of a government to collect them? Even if Christensen's characterization of agricultural productivity levels is correct, does it give a full picture of the economic vitality or weakness of an area if it ignores non-agricultural economic activities? Particularly in the case of Mesopotamia, how much were declines in agriculture offset by increases in trade and commerce? Can the continued process of urbanization there be explained only by the flight of peasants from the troubles of the countryside?

It is safe to say that not all readers, especially traditional political and cultural historians, will be convinced by Christensen's thesis. For this reviewer, however, The Decline of Iranshahr is a refreshing, provocative example of what might be called post-Orientalist scholarship. It provides a welcome and long-overdue corrective to the pro-caliphal and Iraq-centered bias so pervasive in both the textual sources and traditional accounts of early Islamic history.

ELTON L. DANIEL UNIVERSITY OF HAWAII