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One of the most striking features of the High Middle Ages was the dramatic growth of population that took place between roughly 1000 and 1300. Estimates suggest that the population of Europe (excluding the Byzantine Empire) nearly doubled in this period, from approximately 38 million in 1000 to perhaps 74 million by 1300. This was a demographic expansion of historic importance, and it was closely linked to a series of interrelated factors: a favorable climatic period known as the Medieval Warm Period, a series of agricultural innovations that increased the productivity of the land, a decline in warfare and invasion that reduced the loss of life, and the expansion of settlement into new lands across Europe.
This cluster explores the demographic history of the High Middle Ages. The articles in the related long-tail pages provide deeper examinations of specific aspects of population and climate.
The doubling of the European population between 1000 and 1300 is one of the headline facts of the period, and the explanation — better climate, more land, fewer invasions, the agricultural revolution — is uncontroversial. The debate is over how much of the growth to attribute to each factor. William Chester Jordan, in “The Great Famine” (1996), reads the period as a demographic overshoot whose reversal in 1315 was already visible before the plague. B. M. S. Campbell’s “Before the Black Death” (1991) is the modern starting point for the demographic argument. The page below uses both.
The Medieval Warm Period
The Medieval Warm Period (also called the Medieval Climate Anomaly) was a period of relatively warm and stable climate that lasted from roughly 950 to 1250, with regional variations. The warming was not uniform across the globe, but in much of Europe it produced milder winters, longer growing seasons, and more reliable harvests than the centuries before or after.
The evidence for the Medieval Warm Period comes from a variety of sources. Tree rings from old timber, ice cores from glaciers, pollen records from lake sediments, and historical documents all suggest that the period 950–1250 was generally warmer than the centuries before. In the North Atlantic, the Viking settlements in Iceland, Greenland, and even North America (L’Anse aux Meadows) were made possible by the relatively ice-free seas and the milder climate. In Europe, the vineyard was cultivated as far north as England and Poland, and the grain harvest was generally abundant.
The consequences of the Medieval Warm Period for European agriculture were profound. The longer growing season allowed for the cultivation of crops that had previously been marginal, especially in northern Europe. The milder winters reduced the loss of livestock and made it possible to keep animals alive through the winter that would otherwise have been slaughtered. The more reliable harvests reduced the frequency and severity of famine, and the expansion of cultivation into new lands (especially in the north and east) was made possible by the favorable climate.
The end of the Medieval Warm Period came in the late thirteenth and early fourteenth centuries, with a return to cooler and more variable climate. The Great Famine of 1315–1317, caused by a series of unusually wet and cold summers, was an early sign of the new climatic regime, and the famines, plagues, and wars of the Late Middle Ages were in part a consequence of the climatic downturn.
The Agricultural Revolution
The agricultural revolution of the eleventh and twelfth centuries was a series of technical and organizational innovations that dramatically increased the productivity of European agriculture. The innovations included the diffusion of the heavy plow, the adoption of the three-field system, the introduction of the horse collar and the horseshoe, the selective breeding of livestock, and the expansion of cultivation into new lands.
The heavy plow (also called the carruca) was developed in the late Carolingian period and gradually spread across northern Europe in the ninth and tenth centuries. Unlike the lighter Mediterranean plow (the aratrum), the heavy plow was designed to turn over the heavy, wet soils of the North European plain. It had a coulter to cut the soil, a share to lift it, and a moldboard to turn it over. The heavy plow was typically drawn by a team of eight oxen, and it required a substantial investment of capital, which was often provided by the lord or by a group of peasants.
The three-field system gradually replaced the older two-field system in many parts of Europe. Under the two-field system, half the land was planted in the autumn with winter grain (usually wheat or rye) and half was left fallow to recover its fertility. Under the three-field system, the land was divided into three fields: one was planted in winter grain, one in spring grain (usually oats, barley, or legumes), and one was left fallow. The three-field system increased the proportion of land under cultivation in any given year, reduced the risk of total crop failure, and provided a more varied diet.
The horse collar and the horseshoe were crucial innovations that allowed horses to be used for plowing and other heavy work. The horse was faster and more powerful than the ox, and the development of the harness (which distributed the weight on the horse’s shoulders rather than its neck) made it possible for horses to pull heavy loads without choking. The use of horses for plowing increased the productivity of agriculture, especially in the lighter soils where the ox was less effective.
The expansion of cultivation into new lands was another major feature of the period. The Ostsiedlung — the great German, Flemish, and Dutch settlement of eastern Europe — transformed the demographic and political map of central Europe. The Cistercian monasteries, with their great estates, were major agents of agricultural development, draining marshes, clearing forests, and establishing new villages. The English developed a sophisticated system of open-field agriculture and manorial management that produced high yields and supported a growing population.
The Growth of Population
The growth of population in the High Middle Ages was one of the most dramatic in European history. The population of Europe (excluding the Byzantine Empire) was approximately 38 million in 1000, 50 million in 1100, 62 million in 1200, and 74 million in 1300. This is an average annual growth rate of approximately 0.6 percent, which is very high by pre-modern standards and which compares favorably with the rates achieved by the early modern world.
The causes of the population growth are debated, but the major factors are clear. The more abundant and reliable food supply produced by the agricultural revolution supported more people. The decline in warfare and invasion reduced the loss of life and allowed for more stable family formation. The gradual improvement in the diet and health of the population increased the resistance to disease. And the expansion of settlement into new lands made more resources available to the population.
The regional variations in population growth were significant. The most rapid growth was in the northwest of Europe — England, France, the Low Countries, and the Rhineland — where the three-field system was most fully developed and where the new lands were most accessible. The slowest growth was in the Mediterranean and in the east, where the conditions for population growth were less favorable. The northern expansion of settlement was one of the most dramatic features of the period, with the German, Flemish, and Dutch colonization of the lands between the Elbe and the Oder, and the Scandinavian, German, and Polish settlement of the Baltic region.
The consequences of population growth were profound. The expansion of towns was driven by the migration of peasants from the countryside. The expansion of trade was driven by the growing demand for goods and the growing supply of labor. The expansion of settlement into new lands required the development of new institutions, new forms of governance, and new systems of law. The growing competition for land drove down the standard of living of the peasantry in the late thirteenth century, contributing to the social tensions that would mark the Late Middle Ages.
The End of Expansion
The demographic expansion of the High Middle Ages came to an end in the late thirteenth and early fourteenth centuries. The Great Famine of 1315–1317, caused by a series of exceptionally wet and cold summers, marked a turning point. The famine struck across Europe, from England to Italy, and it produced widespread starvation, disease, and social unrest. The famine was followed by a series of epidemics — the sheep scab epizootic, the bovine murrain, and the murrain of fish — that further damaged the food supply.
The Black Death that arrived in 1347 was the most catastrophic event of the Late Middle Ages. The plague killed perhaps a third of Europe’s population in its first visitation, and recurrent outbreaks continued to take a heavy toll for the next three centuries. The demographic catastrophe of the Black Death reversed the long-term growth of population, and it took nearly two centuries for Europe to return to the population levels of 1300.
The causes of the end of expansion are debated. The climatic downturn of the late thirteenth and early fourteenth centuries was a major factor, as was the exhaustion of the most accessible new lands for settlement. The decline in real wages of the late thirteenth century, as population growth outstripped the supply of land, contributed to a decline in the standard of living of the peasantry. The social tensions produced by these pressures — the Jacquerie in France, the Ciompi Revolt in Florence, the English Peasants’ Revolt of 1381 — were signs of the social strains produced by the end of the expansion.
Sources
Principal sources used in this article:
- William Chester Jordan, The Great Famine (Princeton, 1996).
- B. M. S. Campbell (ed.), Before the Black Death: Studies in the “Crisis” of the Early Fourteenth Century (Manchester, 1991).
Further reading:
- R. I. Moore, The First European Revolution (2000), ch. 1.
For a recent single-volume synthesis with full scholarly apparatus, see the relevant chapter of Barbara H. Rosenwein, A Short History of the Middle Ages (University of Toronto Press, 2014).