Three hundred C.E. divides Big Era Four from Big Era Five because the third and fourth centuries were a time of wrenching changes, at least in Afroeurasia where the great majority of humans lived. The most obvious of these changes was the deterioration or collapse of the large states that dominated a good part of Afroeurasia in the last part of Big Era Four.
Also in these centuries, pastoral nomadic peoples of the Inner Eurasian steppes launched a series of invasions and migrations that disrupted social and economic life across much of Afroeurasia for about 300 years.
A third big shift connected to both these developments was a rather sudden downward trend in the hemisphere's population, which started in the third century and lasted until about 600.
Global Trends
If the decades around 300 C.E. represented a key turning point, human kind did not take off in any radical new direction. Several broad trends already underway in the previous era continued throughout Big Era Five:
Global population and the number of cities in the world fluctuated, but the overall trend was still upward. One estimate has global population going from 252 million in 200 C.E. to 461 million in 1500. 1
Centralized states and the economic systems linked to them grew in complexity. A few states emerged that were even bigger than the Han and Roman empires of Big Era Four. The largest of these were the Arab Muslim empire of the eighth century and the Mongol empire of the thirteenth century.
In Afroeurasia, the trans-hemispheric network of commercial and cultural exchange expanded and contracted from one century to another, but in the era as a whole it reached further and grew denser. In Mesoamerica and Andean South America, webs of interchange were also thickening.
In the Pacific region, pioneer families continued to explore from island to island, gradually peopling the great ocean basin.
The number of hunter-gatherers in the world relative to farmers continued to shrink. As farming spread in tropical Africa, Southeast Asia, eastern North America, and the Amazon River basin, villages and towns sprouted, occupations and industries multiplied, and virgin forests slowly retreated before the farmer's axe.
In technology and science we see a slow, steady accumulation of new ideas and tools built for the most part on the achievements of the previous era. Peoples in every part of the world made technological advances of various kinds. In Afroeurasia the best new ideas tended to diffuse quickly from region to region.
All complex societies of both Afroeurasia and the Americas remained generally patriarchal, with adult males dominating social and political life.
Global Developments
Big Era Five also saw several new developments of great importance on a global scale.
Pastoral nomadic peoples of the Afroeurasian arid lands dramatically increased their military and political power. Pastoral armies and migrants periodically challenged and sometimes conquered densely settled regions in Afroeurasia.
Islam, the third major missionary religion after Buddhism and Christianity, appeared in the seventh century and spread widely in Afroeurasia.
China, India, and Europe all emerged as centers of especially intense economic production, commercialization, city growth, and technical innovation. These regional flowerings animated commercial and cultural exchange all across the hemisphere.
Several large centralized states emerged in the savanna and forest lands of Africa south of the Sahara.
Urbanized and intricately organized states appeared in both Mesoamerica and Andean South America, despite the fact that they possessed neither iron metallurgy nor large draft animals.
Humans and the Environment
The human impact on the natural environment of a region has always varied with the size and density of population. One scholar has made the following estimates of population change in Afroeurasia, the Americas, and the world as a whole during Big Era Five.
The graph below encompasses the entire era, plus the last 700 years of the previous era. The population data at the left of the graph are in millions.
Source: Data adapted from Massimo Livi-Bacci, A Concise History of World Population (Cambridge, MA: Blackwell, 1992), 31.
Teachers may ask students to interpret from the graph how world population changed in the first millennium C.E. The graph clearly shows that world numbers started dipping shortly after 200 C.E., then recovered to only about the same level by 1000.
Since population generally moved upward during the previous 3,000 years, then again after 1000, the absence of significant growth during the first millennium C.E. is something of a puzzle. Two factors might account for this pattern:
Most of the large states in Afroeurasia experienced breakdowns in the third or fourth centuries. Associated warfare and economic disruption probably inhibited population growth.
In the late centuries of Big Era Four, the existence of large empires with good communications networks, as well as the surge of interregional commercial exchange, made easier the spread of infectious disease microorganisms from one region to another. That is, an infectious disease ndemic in one region might spread to other regions far away, where humans did not have natural immunities to it and therefore suffered severely. For example, the Plague of Justinian (probably bubonic plague), which hit the Mediterranean region in the mid sixth century, possibly traveled from northeastern Africa. By 600 C.E., this pandemic may have carried off about half the population of western Europe.2
After about 600 C.E., Afroeurasia's population started upward again and from 1000 and 1500 grew beyond any earlier level, rising from around 235 million to more than 400 million.3 The graph, however, shows a noticeable dip in the fourteenth century. Large-scale environmental crises were likely the most important factors.
One was the "Little Ice Age," an extended period of cooler temperatures, shorter growing seasons, and periodic famine that gripped western and central Eurasia.
Another was the Black Death, a plague pandemic that swept across Afroeurasia from China to Europe in the mid fourteenth century and that may have killed a quarter to a third of the population of Southwest Asia, North Africa, and Europe. Like the Plague of Justinian, the Black Death also occurred during a period of heightened commercial exchange across the hemisphere. The chart indicates that Afroeurasia's population grew substantially between 1000 C.E. and about 1340, a time when a surge of urbanization and productivity was taking place in China, India, Europe, and other regions. At the end of Big Era Five, however, the population was only a little greater than it had been in 1340.
The graph also shows that the population of North and South America was much lower than that of Afroeurasia but grew throughout Big Era Five. Whatever factors may have encouraged this growth, such as the rise of prosperous city-states and empires in Mesoamerica, the Atlantic and Pacific Oceans happily isolated American peoples from the disease pandemics that raged across Afroeurasia.
Population and the Environment
In our own era human efforts to shape and control the environment have intensified along with the continuing acceleration of the world's population growth rate. If intervention in the operations of the biosphere has always been linked to population growth and density, then we can infer that in Big Era Five human impact on the natural and physical landscape in particular regions fluctuated. It was greater when humans were building states and cities and opening new land. It diminished when population shrank, economic production declined, or states disintegrated.
When interregional communication routes were active, traveling, conquering, or migrating people introduced plants and seeds into regions where they were previously unknown. If the climate of the new setting was right, they might flourish. In Big Era Five, for example, the grain crop sorghum was introduced from eastern Africa to China, citrus fruits spread from Southwest Asia to Spain, and cane sugar advanced from India to the Mediterranean.
Also in this era, societies in both Afroeurasia and the Americas developed technologies to better manage water. These techniques included aqueducts, canals, and underground channels; devices for lifting water; and methods of irrigating crops and draining land. These advances produced bigger yields of food and fiber crops in the major agrarian regions, allowing both farming and urban populations to grow and altering the face of the earth.
Human action also damaged the landscape. Scholars have documented surges of deforestation, which was often closely linked to state-building, urbanization, and expanding commerce. Large-scale deforestation occurred, for example, in the Roman empire, the Muslim empires of Southwest Asia and North Africa, and the Chinese empire under a succession of dynasties.4 Deforestation led to wood shortages for heat, construction, and metal smelting, and caused long-term soil erosion.
Forest clearing in Roman Italy, for example, caused irreversible soil degradation and contributed to serious food shortages in the third and fourth centuries. In China deforestation that accompanied urbanization and economic expansion contributed to river flooding, which devastated villages and farmlands. The incidence of flooding on China's major rivers appears to have increased quite steadily in Big Era Five.
Humans and Other Humans
Although the number of farmers and pastoralists in the world hugely increased in this era relative to the number of hunter-gatherers, the life ways of agrarian societies did not change fundamentally from the previous era.
No great transformations took place in the way people farmed, manufactured, created states, built cities, or traveled, at least not compared to the stunning changes that have occurred in the world in the past 300 years.
We see in Big Era Five, rather, a fairly steady though somewhat intermittent accumulation of innovations in the ways humans organized production, social life, and communication. In other words, human capacity for collective learning continued to accelerate though perhaps more modestly than in the previous era.
Technology
For example, the era witnessed numerous improvements in Afroeurasia in the technology of transport and communication, notably in the design of sailing ships and gear for controlling draft and riding animals. The handiest ideas tended to diffuse quickly from the place where they were first invented. Key inventions of the era included:
the stirrup
the North Arabian camel saddle
the horse collar harness
the stern-post ship rudder
the triangular lateen sail
the astrolabe
the compass
the portolan map
Teachers may ask students to investigate the origins, uses, and spread of these inventions. The point needs to be made, however, that despite the improved reliability and efficiency that these novelties introduced, humans could not walk, ride, sail, or dispatch messages much faster at the start of Big Era Five than at the end.
Changing Civilizations
As we have mentioned, several large Afroeurasian states collapsed in the third and fourth centuries, but new ones then arose. In fact, Big Era Five was a kaleidoscopic scene of city-states, kingdoms, and empires appearing and disappearing. Some new rulers built on the foundations of previous dynasties, and some created large, multiethnic states in regions where none had previously existed.
State-building was noticeably active in Europe north of the Alps, Africa just south of the Sahara, and Southeast Asia, especially in the last 500 years of the era. Owing to the technological limits of transport and communication, the largest states of Big Era Five were not on the whole bigger than those of the previous era. The two major exceptions in Afroeurasia were:
the Muslim Arab empire, which for a time in the eighth century extended from the western Mediterranean to India.
the Mongol empire forged by Chingis Khan (Genghis Khan) in the thirteenth century. At its height around 1260 C.E., it stretched from Korea to eastern Europe.
The comparisons below show the astonishing scale of the Arab Muslim and Mongol states.6 On the other hand, neither state lasted as a unified empire more than about half a century. The outer areas of the Arab Muslim empire soon broke away from the central lands. In the Mongol case, Chingis Khan's sons and grandsons launched wars against one another within about thirty years of the great conquerors death. Those struggles led to the dismemberment of the realm into four Mongol-ruled monarchies.
State
Approx.
Year
Approx. size in
square miles
Roman empire
100 C.E.
1,698,400
Arab Muslim empire
750 C.E.
4,246,000
Sung empire (China)
1000 C.E.
1,158,000
Mongol empire
1250 C.E.
6,948,000
Inca empire (Andes Mts.)
1500 C.E.
772,000
Continental United States
present
3,021,296
The rise of the Mongol empire was one episode in a larger pattern of events that characterized Big Era Five: periodic clashes between well-armed nomadic peoples and settled agrarian societies of Afroeurasia.
At different times during the era, Germanic folk, Huns, Arabs, Turks, Berbers, and Mongols moved out of Inner Eurasia or the Sahara Desert to invade urban agrarian regions of Afroeurasia. In the short term, these invasions were always disruptive to the extent that nomad cavalry sacked or occupied cities, overthrew existing governments, or in some cases killed many people or drove peasants off their land.
In the longer term, however, these aggressions tended to strengthen and extend contacts among people in different parts of the hemisphere and to stimulate the circulation of goods and ideas over long distances.
In fact, neither invasions from the steppe nor the disintegration of imperial regimes prevented an interconnected system of commercial and cultural interchange from emerging in Afroeurasia as a whole by the end of Big Era Five. This network, visible in the long-distance movements of wagon trains, camel caravans, and sailing ships, bridged the Inner Eurasian steppes, the Sahara Desert, and the Indian Ocean.
Trade and Economics
The merchants of the era operated less as agents of governments and more as independent, profit-seeking entrepreneurs. They traded over long distances in bulk products (grain, metal ore, fish, timber, coarse textiles) and more precious commodities and manufactures (gold, gemstones, spices, silks, porcelain, glassware, ivory). This trade tightened economic relationships and stimulated production in all regions that had tradable resources.
In the period of remarkable economic growth in Afroeurasia between 1000 and 1500 C.E., China (silk, porcelain) and India (cotton textiles) were the biggest manufacturing centers. Also, western and central Europe emerged as a new center of population growth, urbanization, and commerce. The Muslim lands of Southwest Asia served as the turnstile of the hemisphere, its cities generating their own finished goods and transshipping wares in huge quantities from one part of the hemisphere to the other.
As commerce grew, peoples of Japan, island Southeast Asia, equatorial Africa, and far northern Europe became increasingly linked into its web. As one example, the state known as Great Zimbabwe rose to power in the savannas of southern Africa in the thirteenth century. Its prosperity derived partly from the sale of locally mined gold to merchants on the Indian Ocean coast, who traded this scarce commodity far and wide.
Understanding how extensive and sophisticated the trans-Afroeurasian exchange network had become by 1500 C.E. offers students a fresh perspective on the next era, when Christopher Columbus and other intrepid mariners sailed across the Atlantic and Pacific Oceans and around the Cape of Good Hope.
In this light, the maritime "discoveries" of the fifteenth and sixteenth centuries appear as efforts by business-minded Europeans, who drew on Afroeurasia's accumulated transport and navigation skill, to play a stronger hand in the trans-hemispheric system. In the process some of these Europeans stumbled on North and South America.
Humans and Ideas
In the previous era, six of the world's major belief systems took shape, and all of them spread among peoples of diverse languages and local cultures. In the early centuries of Big Era Five, Christianity and Buddhism, more than the other four systems, emerged as universalist, missionary religions. This means that their devotees transcended association with a particular state, ruling class, or ethno-linguistic group and actively proclaimed their message to anyone who would listen.
Religion
In the seventh century C.E., Islam joined these two faiths as the third universalist religion after Arabic-speaking invaders galloped out of the Arabian Desert to overrun the Persian empire and a large part of the Eastern Roman (Byzantine) empire.
These conquerors founded a large state of their own, based first in Damascus, then in Baghdad. The new rulers of Southwest Asia also proclaimed Islam, a faith that embodied a scrupulous monotheism and moral code based on a scriptural tradition that intersected with Judaism and Christianity.
Though the giant Arab Muslim empire of the eighth century soon broke into smaller political units, Islam continued to spread within the territory the empire encompassed and much beyond. In the following two centuries, Islam became the dominant faith from Spain and North Africa to Afghanistan.
Like the other world religions, Islam also came to embody a distinctive style of complex urban culture. At the heart of this civilization was the Arabic language and a developing Muslim cultural tradition. But it also drew extensively on the earlier intellectual, moral, and artistic traditions of the Greeks, Persians, Christians, and Jews.
What about the other major religions in Big Era Five?
Christianity gave way to Islam as the most widely-practiced universalist religion in Southwest Asia and North Africa. But Christianity became dominant throughout Europe and succeeded in such places as Ethiopia and Inner Eurasia.
Buddhism also declined in India, the land of its birth, but it spread from India to China, Korea, Japan, and mainland Southeast Asia.
Hinduism, which experienced a great resurgence in India relative to Buddhism during the Gupta Empire (fourth and fifth centuries), continued to be closely associated with Indian society and culture, though also enjoyed favor among some ruling groups in Southeast Asia.
Similarly, the Daoist and Confucian belief systems remained deeply rooted in China but also developed influence in Korea and Vietnam.
At the start of Big Era Five Jews were practicing their monotheism and ethical code in communities from the western Mediterranean to Inner Eurasia. Though Jews did not actively seek converts in the manner of the three universalist faiths, Jewish communities multiplied in medieval Europe and generally prospered in Muslim-ruled lands. The monotheism of the Jewish faith was the same that inspired the revealed religions of Christianity and Islam, We can classify those three belief systems, plus Buddhism and Hinduism, as religions that offered humans eternal salvation, though in varying forms.
We have limited understanding of belief systems in the Americas in Big Era Five owing to the catastrophic population decline that occurred there in the sixteenth century and to the dearth of written evidence.
Nevertheless, the archaeological record shows that certain religious beliefs and practices spread widely among different ethno-linguistic groups in Mesoamerica, as well as in Andean South America and the eastern woodlands of North America.
It is also significant that all the major religions of the era tended to thrive in cities and their hinterlands and to spread along major trade routes. In parts of the world that were far from big cities and busy routes people continued to practice local religions that often involved worship of gods and spirits associated with nature.
Philosophy
Big Era Five was not a time of intellectual and scientific revolution, but new ideas of how to observe and explain the natural and physical world continued to accumulate.
The Hellenistic (Greek-derived) system of inquiry known as natural philosophy, which we described in connection with Big Era Four, continued to have much intellectual power in Big Era Five in Muslim Southwest Asia and Christian Europe. Muslim, Jewish, and Christian scholars in Baghdad and other Southwest Asian cities developed a new body of ideas, notably in mathematics, astronomy, philosophy, and medicine that synthesized and built upon Greek, Persian, Mesopotamian, and Indian knowledge.
In the late centuries of the era, European scholars adopted much of the Muslim synthesis and reconciled Hellenistic and Christian understandings of nature and the cosmos. In the period of the Gupta era, India glittered as a center of mathematical innovation that included the ten-base numerical system and the concept of zero we use today.
These and other ideas eventually spread throughout much of Afroeurasia. Chinese scholars of the era ranked high as producers of knowledge in astronomy, chemistry, and medicine. Archaeological evidence has given us glimpses of the sophisticated mathematics and astronomy of Mesoamerican sages, notably in the Maya city-states.
In Afroeurasia, Big Era Five saw formal educational institutions and networks for collective scientific learning emerge and spread.
In China, especially beginning with the T'ang dynasty in the sixth century, the path to scholarly recognition and government office was the imperial examination system, which rewarded those who demonstrated intricate knowledge of Confucian ethics and statecraft.
We can look to the Muslim and Christian European worlds for the early foundations of the modern university as a place where teachers and students came together to study, work, and live as an intellectual community. The college as a corporate institutions of scholars and students first developed in Muslim lands after 1000 C.E. and spread from there to Europe.
