Environmental interpretations of social history have become a matter of growing scientific interest. In this respect, pharaonic Egypt is among the richest as well as unique fields of research: besides the Nile Valley, there were few regions in the ancient world where everyday interdependence of man and nature has been so close and effective a factor in the social and political genesis. The extent of our knowledge about the ecology of Ancient Egypt allows us to begin a dynamic reconstruction of the environmental conditions during the emergence of pharaonic civilization as well as through its several thousand-year evolution. At the same time, the importance and true range of natural processes which influenced Ancient Egyptian history have yet to be sufficiently estimated. In other words, the environment in its transformations has never been interpreted by scholars as one of the main characters in the "dramatic theater" of pharaonic civilization. This can partly be explained by the omission of relevant information or, even, the use of obsolescent scientific data. Examples of this include, among others, information on the changes of the Holocene climate. This monograph presents an important first step in the socio-ecological history of Ancient Egypt in the chronological limits from the Fourth to Second Millennium BC (all dates in this Summary are calendar).
         This research bases itself upon the latest reconstruction of the Holocene temperature fluctuations in the Northern Hemisphere by Prof. V. V. Klimenko & colleagues (Moscow Institute of Energy). This reconstruction permits us to see that, in addition to the notorious desiccation of the late Third Millennium BC, followed by a series of severe droughts in the Nile Valley, the Egyptian climate during the pharaonic time passed through several considerable variations which have been overlooked until now. Besides, this up-to-date palaeoclimatological model presents us with quite new ideas of influence upon the historical development of Ancient Egyptian civilization of climatically conditioned environmental processes, such as the eustatic Ocean level oscillations and changes of the Nile flood discharge, among others.
         The fundamental point of the conception of pharaonic socio-ecological history herein is the idea of a series of three socio-ecological crises which originated in the resonance of destructive social-political tendencies as well as disastrous environ-mental transformations in Egypt. Since most of the scientific data used in this research has never been used for the Egyptological purposes, this monograph focuses attention deliberately on the ecological aspect of the research.
         The First Socio-Ecological Crisis which resulted in the emergence of the centralized state in Egypt is linked here, first of all, with the Mediterranean trans-gression in the Nile Delta within the post-glacial (Flandrian) eustatic transgression of the World Ocean. According to most of the geo-physical theories, Flandrian trans-gression approached its upper level in the Fourth Millennium BC, several centuries after the culmination of the Atlantic Climatic Optimum, the warmest episode of the Holocene (with a mean global temperature 1,4°C higher than today). In the light of D. Stanley's lithostratigraphic explorations in the Nile Delta, in the Fifth Millennium BC, when the sea level was about 10 m lower than today, the Delta appears to have been dry and quite suitable for farming and livestock herding. Favorable ecological conditions in the neolithic Lower Egypt should have attracted numerous migrations from the Western and Eastern Deserts which would have been driven by the desiccation of North Africa which started in the late Fifth Millennium BC. In the first half of the Fourth Millennium BC, the socio-economical development of the Delta seems to have outrun considerably that of Upper Egypt; in addition to this, the predynastic settlement of the Valley was obviously delayed by extremely high Nile floods and, on the contrary, by still quite comfortable ecological living conditions in the vicinities of the Nile floodplain.
         According to Herodotus, however, in the time of the first Egyptian kings, the Delta was totally inundated; in conformity with this information, the archaeological data show that the early Egyptian state was born in the Valley. It is suggested here that the Delta was inundated by the catastrophic Mediterranean transgression which drastically changed the geo-political situation in Egypt. Substantial reduction of the living space in Lower Egypt, approximately in the late Gerzean period, is considered as one of the main preconditions of the First Socio-Ecological Crisis of Ancient Egyptian civilization.
         To estimate the effect of the rising sea upon the Delta in the Fourth Millennium BC, different reconstructions of the eustatic process in the Holocene were taken into account in this research. Not long ago, they were all brought to a couple of initial models. According to R. Fairbridge's version, in the Fourth Millennium BC, the Ocean level surpassed the modern one by 3-4 m and, since then, has experienced damped oscillations within the limits of ±1-3 m. The alternative theory of F. Shepard suggested that the post-glacial ocean has never exceeded its modern level but approached it "exponentially". The subsequent discoveries of tectonic, isostatic, geoidal as well as other eustatic factors revealed geographical and temporal dis-similarity of the Holocene eustasy dynamics; in particular, different shorelines showed both an increase of the post-glacial sea levels above the modern one as well as the absence of such an uprise. At the same time, the up-to-date lithostratigraphy of the Nile Delta allows us to suggest that, in both cases, the Delta must have suffered a catastrophic inundation at the peak of Flandrian transgression in the Fourth Millennium BC.
         The transgression hypothesis provides us with quite new possibilities of inter-pretation for the emergence of statehood in the Nile Valley and, simultaneously, a new explanation for the phenomenal capture of 120 thousand men by the 0-dynasty King Narmer in Lower Egypt (according to K. Butzer's estimations, more than half of the Delta population!). This figure (if not symbolic) is too enormous to believe in its adequacy with the range of tribal wars, but looks absolutely realistic if we suppose that the "captives" were refugees who migrated from the ecologically degraded Delta on a mass scale as the culmination of the Mediterranean transgression approached. It is just that very demographic phenomenon which could be linked with the origins of state in Egypt: in a short time period and, apparently, for the first time in history, one of the Egyptian tribal communities grew in such a proportion that its survival demanded a prompt hierarchization which, in turn, finally brought Narmer's chiefdom to the state-forming level of the social stratification. At the same time, in the case of protodynastic Egypt, since the population growth necessary for state formation had probably been a local anomaly, the so-called Early Kingdom state (the First and Second Dynasties) is likely to have been a kind of advanced social subsystem inside the Egyptian nation, occupying primarily a limited territory of Egypt and, for two-three centuries, gradually expanding its hegemonic position over the rest of the country. Proceeding from this theory, the Early (Thinitic) Kingdom of Egypt should be defined as the "0 Intermediate Period" according to the mature centralized state which emerged not before the Third Dynasty. Thus, the Egyptian social-political system under the First and Second Dynasties better qualifies as the bifurcational "early state".
         The mass migration of people from the submerging Delta into Upper Egypt in the protodynastic time is likely to have been favored by the improvement of ecological conditions in the Valley after the so-called "Neolithic drop" of the Nile. This process ended, presumably, on the threshold of the Second Dynasty and its final stage is probably fixed by the Nile flood-level records of the Palermo Stone. Diminishing of the level and area of the river floods, on the one hand, could have eased the social cataclysm of the mass migration; on the other hand, it could have helped the development of local hotbeds of basin irrigation in the Nile floodplain into a kind of network and further integration of Egyptian population.
        Besides eustatic transgression, the predynastic epoch witnessed a global climate change. The Atlantic Climatic Optimum with its moistening was followed by a steep fall of temperature in the Northern Hemisphere during the Fourth Millennium BC; in particular, this fall was accompanied by the settling of arid conditions in the Northeast Africa. It should be stressed, however, that until approximately 3800-3700 BC, the
climate of Egypt is considered to have remained rather warm and moist. Sharp cooling happened only ca. 3600 BC; it is noteworthy that this climatological landmark coincides with the rough date of considerable social and technological progress in the Nile Valley which is associated with the transition from Naqada I (Amratian) to Naqada II (Gerzean) archaeological cultures in Egypt. The minimum temperature (about 2,4°C less than at the peak of the Atlantic Optimum over a thousand years before) was reached ca. 3190 BC. Since the Egyptian climate at that time is con-sidered to have become much drier and probably slightly hotter than today, it follows that the emergence of state in Egypt took place in drought conditions which could have been the supplementary factor of the supposed political immaturity of the "Early Kingdom".
         Ca. 3000 BC the climate of Egypt became more moist and remained so until ca. 2900-2800 BC. This was followed by a short-term episode of dry conditions, apparently synchronous with the "dark age" of the late Third Dynasty. Sometime under Snefru, the founder of the Fourth Dynasty, abundant rainfall had set in Egypt; this precipitation growth marked the beginning of the Subboreal Climatic Optimum whose first peak embraced the reign of the Fourth and Fifth Dynasties. Warm and moist climate provided sufficient Nile discharge as well as productive agriculture in the Nile floodplain, thus being one of the main factors of comparative socio-ecological stability and durability of the centralized state in the Egypt of the Old Kingdom.
         Among the factors of the socio-ecological stability in the Old Kingdom, the hypothetical Mediterranean regression in the Third Millennium BC takes an important place. The scientific data and information of the written sources allow us to raise the question that in the time of the Third-Fifth Dynasties, the sea was receding and clearing more and more area of the Delta. It is argued here that this regression stimulated the return wave of settlement of Lower Egypt (obviously together with the population growth) and facilitated the drainage works and extensive farming in the Delta in the first half of the Old Kingdom. Besides, starting with the Fifth Dynasty, retreat of the Mediterranean is likely to have induced the kings to endow temples and high officials with lands in Lower Egypt; this "generosity" was probably one of the factors restraining the political crisis and centrifugal forces in the late Old Kingdom.
         Decline of the Old Kingdom was accompanied by environmental deterioration in Egypt. Under the Sixth Dynasty, the development of the Subboreal Climatic Opti-mum was interrupted by a fall of global temperature, with culmination ca. 2055 BC and at about a 0,5°C total temperature decrease. As a result, the climate of Northeast Africa became much drier, the rainfall ceased, deserts came close to the river valley, sand dunes began to invade the cultivable floodplain, the ground-water table sank, the Nile discharge and, correspondingly, flood levels reduced. Archaeological sources reveal simultaneous symptoms of progressive economic crisis in Egypt. Local power, together with distributive function, came to pass into the hands of nomarchs; politically, the Old Kingdom was tending toward disintegration.
         Obviously, some radical reforms in the social structure of Egypt of the post-Old-Kingdom time could have been induced by the ecological catastrophe of the last half of the Third Millennium BC. Thus, it is seen here that progressive reduction of the Nile flood level stimulated the first experiments of the substitution of professional "individual" cultivators for non-specialized gangs of workmen in agriculture. At the same time it should be stressed that the reason for the social-political crisis in the late Old Kingdom is certainly not due exclusively to ecological factors. Moreover, contrary to the wide-spread point of view in the light of modern palaeoclimatological reconstructions, severe droughts and very low Nile levels had nothing to do with the break-up of the Old Kingdom: decline of the centralized state began 150-200 years before the culmination of this famous ecological catastrophe which, in fact, coincided with the emergence of the Middle Kingdom in Egypt.
         The epoch of the First Intermediate Period and Middle Kingdom is called here the Second Socio-Ecological Crisis of Ancient Egyptian civilization. The First Inter-mediate Period was characterized by drastic desiccation of the Nile drainage-basin, the reduction of Nile discharge to a minimum during the pharaonic time, and the considerable fall of the level of Lake Moeris in the Fayum depression. Environmental disaster and political disintegration of Egypt disturbed the irrigation infrastructure of the country. Famine and internal wars seem to have devastated some regions of the Nile Valley. The Egyptian community found itself in natural and social conditions which demanded the search for quite different strategies of adaptation and principles of self-organization. The Second Socio-Ecological Crisis was an epoch of the working-out and strengthening of such strategies and principles, the civilizational bifurcation between the half-archaic Old Kingdom, and the advancing New Kingdom "Empire".
         According to hypothesis proposed here, one of the fundamental stages of this reorganization was the revolution in irrigation technology connected with the in-vention of the derivation channels which brought the Nile water to the so-called "high lands" outside the floodplain. The first mention about these channels in Egyptian writings occurs in the First Intermediate Period - the time of the lowest Nile levels in the pharaonic history. Thus, these channels are seen as having a kind of "response" to the catastrophic drop of the Nile discharge and the means to compensate the loss of the most productive, naturally flooded lands in the Nile Valley. Adapting to the new living conditions, Ancient Egyptian society turned to the regular anthropogenic trans-formation of its containing landscape.
         The culmination of the "hydraulic revolution" in Egypt in the time of the Second Socio-Ecological Crisis occurred in the Twelfth Dynasty by the unique irrigation system in the Fayum oasis which allowed artificial irrigation in part of the cultivable territory of Lower Egypt, including providing the necessary Nile level in years of low Nile discharge. Together with derivation channels, the Fayum irrigation network, based on the renewable water resources of Lake Moeris, must have favored the increase of resistibility of the Ancient Egyptian socio-economic system to disastrous environmental changes, in particular, those of climate influencing the regime of the Nile. At the same time, one should note the controversial nature of the wide-spread point of view that the newly-drained area in the Middle Kingdom Fayum appeared to have become a granary promoting the prosperity of Egypt as a whole. The culculation showed that the new lands developed in the Fayum depression in the time of the Twelfth Dynasty could supply food, on the peak of their crop capacity, to only about 55 thousand men - obviously, the population of the kings' domain situated in the Middle Kingdom epoch in the Fayum oasis and its vicinities. Rich and economically stable Fayum which made kings exclusively wealthy compared to any nomarch, was apparently one of the main preconditions of the central power growth. This, in turn, favored not only the return of Egypt from "feudalism" to the centralized state, but may be also explain one of the emerging trends of much more unified so-cial-political organization - a characteristic feature of the so-called New Kingdom "Empire".
         The mechanism of power unification in the context of the discussed irrigation innovations in Ancient Egypt during the Second Socio-Ecological Crisis could have occurred as follows: according to Herodotus, it took six months to refill Lake Moeris up to the volume which allowed the effective watering of the area embraced by the irrigation network of the Fayum hydraulic system. It is likely that, to guarantee the sufficient water income to the Lake, the spontaneous digging by the Upper Egyptian nomarchs of the channels, thereby taking water away from the Nile, should have been suppressed by the kings. As the real power in Ancient Egypt was neccessarily connected with the right to exercise control over irrigation, depriving nomarchs of such a right was equivalent to abolishing of one of the basic principles of their might and sovereignty which was not eliminated even by the strongest Fourth Dynasty and supported the "feudal"-political structure of the intermediate stage between the Old and New Kingdoms. Thus, the aspiration of the pharaohs of the Eleventh-Twelfth Dynasties for total control over the irrigation infrastructure of Egypt may have been one of the preconditions of the final suppression of the nomarchs-landowners as well as the transition of the Ancient Egyptian political system to a more hierarchized and centralized state administration of the "imperial" pattern in the New Kingdom.
         At the same time a working hypothesis is suggested here that the most difficult living conditions in the Egypt of the Second Socio-Ecological Crisis forced the rulers (nomarchs during the First Intermediate Period and, later, pharaohs of the Middle Kingdom) to "descend from the pedestal" and take an active role in the everyday life of their subjects. This could have favored the loss, postulated by J. Posener, of tra-ditional Egyptian beliefs in the divinity of the Pharaoh - the formerly inalienable attribute of the state ideology of the Ancient Egyptian Old Kingdom.
         Reverting to palaeoecology, it is necessary to consider that, in the early Second Millennium BC, the global temperature rise recommenced, and, ca. 1800 BC, the upper peak of the Subboreal Climatic Optimum set in with the total temperature growth of 1,8°C compared to the cold climatic anomaly of the late Fourth Millennium BC. This warm stage was characterized by the highest wet levels of Northeast Africa for the last 5000 years; following the increase of precipitation, the Nile discharge is estimated to have grown almost twofold. It is noteworthy that this episode of comfortable environmental conditions in Egypt coincided chronologically with the "golden age" of the Middle Kingdom (i. e. the Twelfth Dynasty).
         This climatic optimum, however, was rather short-termed: with the following several decades, the next temperature fall began and, as a result, Egypt in the late Middle Kingdom could have suffered a series of severe droughts and crop failures along the lines of the First Intermediate period. Up to ca. 1680 BC, the global tem-perature decreased almost by 0,6°C. From then, until the end of the New Kingdom, the temperature oscillated closely to the modern values. Thus, the ecology of the New Kingdom was characterized by comparative climatic invariability which was one of the main environmental conditions of the socio-ecological stability during the reign of the Eighteenth-Nineteenth Dynasties, the time "when Egypt ruled the East".
         The collapse of the New Kingdom under the Ramessides (i. e. Twentieth) Dy-nasty is discussed here in the context of the Third Socio-Ecological Crisis of Ancient Egyptian civilization. The starting point of the argument was K. Butzer's reconstruc-tion of the alluvial Nile floodplain formation and, in particular, the assumption that in the Second Millennium BC (owing to the cessation of the monsoon rains in Ethiopia), the silt deposition in the Nile Valley was interrupted. Lack of silt, the natural fertilizer of Egyptian soils, must have had a certain effect on the cultivable alluvial lands: their quality must have fallen. Being interpreted in the light of this supposition, the data of the Wilbour Papyrus - the great cadastre compiled in the reign of Ramses V - allows us to hypothesize that the alluvial land productivity in Egypt of the New Kingdom was reduced by half in the time of Ramessides. The exhaustion of lands, together with population growth, demanded the development of additional agricultural areas. Just with the land deficiency caused by gradual degradation of soils in the Nile floodplain, the extensive working of the so-called "high lands" during the New Kingdom and the total cultivation of the Delta under Ramses II could be connected. The last measure seems to have improved the situation in Lower Egypt. Despite this, however, the socio-ecological crisis progressed: settled for centuries, in different ecological and social conditions, the structure and working mechanisms of the New Kingdom agriculture were damaged irreversibly. The written sources mention a large lack of crop revenues to the state granaries, mass ruin of "individual" farmers, and admini-
strative repressions of tax defaulters. The economical decline and progressive political disorder in Egypt undermined the pharaohs' authority in Asia and Nubia. Finally, the Third Socio-Ecological Crisis culminated in disintegration of the centralized Egyptian state.
        In the First Millennium BC, the Nile floods increased, and accelerated depo-sition of silt in the Nile floodplain took place. This phenomenon is likely to be con-nected with temperature growth of the early Tenth - late Ninth Centuries BC. Infor-mation of Ancient and Egyptian written sources allows us to estimate the silt accumu-lation in the Third Intermediate Period - Late Kingdom Egypt as twofold in com-parison with that of the Old - New Kingdom time. Accelerated silting was also characteristic for the predynastic Egypt. Finally, it is postulated here that pharaonic civilization emerged and developed within strictly limited period of geo- and hydro-logical history of the Holocene Nile Valley, notable for the minimum rate of alluvium deposition in the river floodplain in the historical epoch. If Egypt herself was "the gift of the Nile", Ancient Egyptian civilization was "the gift of the flood" and could survive only under the condition of optimum (or close to it) correlation between flood levels and level of the floodplain terrace, which ensured a sufficient area of natural irrigation or, at least, allowed to do with the most simple means of artificial irrigation of the "high lands". Such a correlation seems to have been settled after the so-called "Neolithic drop" of the Nile in the late Fourth Millennium BC and broken in the First Millenium BC, what must have resulted in the decline of the working irrigation system and demanded from the Late Egyptian population radical administrative, eco-nomical and technological reorganization. It is just this reorganization, in which the final political collapse of the pharaonic Egypt is hypothesized to have been rooted.
[To be continued].
Dmitry Proussakov

Criticism and proposals are welcome: prusakov@prusakov.msk.ru