land. When such changes occurred over a wide region, entire
peoples could disappear. Some of these changes were caused
by human activity. When farmland was overworked or for-
ests were cleared, the result was soil erosion, fl ooding, and
other disruptions that wiped out communities. Of course,
these changes worked in the other direction; as land formerly
covered by glaciers warmed and the glaciers receded, new
communities of people moved in.
Wa r fa re , too, oft en led to the collapse of societies. For
nearly 3,000 years, Egypt stood at the summit of human civili-
zation. But beginning in the Late Dynastic period Egypt could
no longer defend its empire. Successive wars and occupations
by the Assyrians, Persians, and fi nally Greeks led to the end of
dynastic rule and the collapse of Egypt as a major world power.
Th e Romans suff ered a similar fate when their empire split un-
der the weight of its own sheer size and fi nally collapsed when
it could no longer fend off Germanic peoples from the north.AFRICA
BY MICHAEL J. O’NEAL
Th e peoples of ancient sub-Saharan Africa lived primarily as
hunter-gatherers until about the second century b.c.e. Ac-
cordingly, they did not form cities or permanent settlements
that expanded into empires or dominant civilizations. Hous-
ing and other structures were built with temporary material,
such as mud and wattle, rather than the stone and brick used
by some other cultures. Th us, little can be known in detail
about the collapse and abandonment of settlements in the an-
cient sub-Sahara, although social scientists can make infer-
ences about the processes that led them.
One such process was probably environmental degra-
dation. Although the sub-Sahara was rich in resources that
allowed people to subsist and even thrive as hunters and gath-
erers, it was inevitable that as the population of a given area
increased, resources were strained, particularly the food sup-
ply. As game animals became scarcer and native plants were
exhausted for their food value, communities would simply
pick up, abandon the region they inhabited, and move on to a
new region, where the process began again.
Similar processes aff ected the ironworking cultures of
the sub-Sahara. Th is region was unique in that it seems to
have skipped the Bronze Age that was so important to the
development of other world cultures and passed directly
from the Stone Age to the Iron Age. Iron smelting, how-
ever, requires high heat in furnaces. Th e most common fuel
used to fi re these furnaces was wood—and wood in massive
amounts. Th e result was deforestation in the area immedi-
ately surrounding an ironworking community. As time went
on, fi rewood had to be brought to the site from farther and
farther away. Th is deforestation led to soil erosion and the
disappearance of game, making it increasingly diffi cult for
surrounding populations to feed themselves.
Another process that led to social collapse and abandon-
ment was climate change. Th e most noteworthy example inancient Africa had to do with the Sahara. For thousands of
years this vast region has been a harsh, forbidding desert. It
was not always this way. Until about 3000 b.c.e. much of the
Sahara was fertile grassland that supported populations of
people. In the area that is modern-day Mauritania, for ex-
ample, an early Berber culture called the Bafour survived by
farming and grazing herds. Th en the climate began to change,
the rains disappeared, and the desert grew relentlessly south-
ward (overcultivation and overgrazing of the land may have
contributed to its decline). Th e Bafour had to abandon the
region. Many people simply moved to urban centers, includ-
ing those of Egypt, where they and their descendants forged
a new kind of life. Historians believe that the descendants of
the Bafour include the Imraguen, who became fi shermen on
the African coasts; the Toucouleur, who moved to Senegal;
and the Wolof peoples, who settled in Gambia, Senegal, and
Mauritania. All three of these ethnic groups survive in the
21st century. Th e process was intensifi ed as the Berber people
from the north, themselves facing environmental degrada-
tion and political turmoil, expanded southward in the third
and fourth centuries c.e., driving out surviving members of
the indigenous groups. Th is example illustrates the complex
movement of peoples as they faced crisis, abandoned their
communities, and were absorbed into other cultures.
Disease and famine, too, contributed to the collapse of
ancient African civilizations. A noteworthy example is the
Nok civilization, which emerged in modern-day Nigeria in
about 500 b.c.e., survived into the Common Era, and then
mysteriously disappeared. Th e Nok were an advanced civili-
zation best known for ironworking and, especially, terra-cotta
sculptures. Historians do not know with any certainty why
the Nok simply disappeared, but they speculate that famine
or disease led to a sharp decline of the population and the
merger of the Nok with the Yoruba people. Famine and dis-
ease are mutually reinforcing; food shortages make hungry
people more susceptible to disease, and as people die, less and
less food can be produced. A civilization weakened in this
way could not survive.
Finally, warfare and the desire for empire led to the col-
lapse of African civilizations. A good example is provided by
Kush, a region just south of the Egyptian Empire. Th e Kush-
ites developed a fl ourishing culture between about 1700 and
1500 b.c.e., primarily because Egypt was under the control of
the Hyksos, a Semitic people from Asia. However, when the
Egyptians expelled the Hyksos, they set their sights on Kush,
wanting control of the region not only as a buff er to protect
their southern border but also as a trading colony. Th en, in
about 1000 b.c.e., the Kushites again asserted their indepen-
dence, unifi ed their kingdom, moved their capital city up-
river (that is, to the south, since the Nile River fl ows south to
north) to Napata, and became a major power in the region.
Th ey had access to rich gold mines and grew so strong that
they attacked and conquered Egypt for a time.
However, this power was not destined to survive. Kush
came under attack from the Assyrians and later the Persians.social collapse and abandonment: Africa 9990895-1194_Soc&Culturev4(s-z).i999 999 10/10/07 2:30:42 PM