The origins of the human race are traced from anthropoid ancestors to the agricultural revolution.

Egyptian irrigation created one of the first great civilizations.

Settlements in the Fertile Crescent gave rise to the great river civilizations of the Middle East.

Metals revolutionized tools, as well as societies, in the empires of Assyria, Persia, and Neo-Babylonia.

Democracy and philosophy arose from Greek cities at the edge of the civilized world.

Socrates, Plato, and Aristotle laid the foundation of Western intellectual thought.

Alexander's conquests quadrupled the size of the world known to the Greeks.

Hellenistic kingdoms extended Greek culture throughout the Mediterranean.

Through its army, Rome built an empire that shaped the West.

Rome's civil engineering contributed as much to the empire as did its weapons.

Christianity spread despite contempt and persecution from Rome.

The old heresy became the Roman empire's official religion under the Emperor Constantine.

While enemies slashed at Rome's borders, civil war and economic collapse destroyed the empire from within.

Despite the success of emperors such as Hadrian and Marcus Aurelius, Rome fell victim to barbarian invasions.

From Constantinople, the Byzantine Empire carried on the traditions of Greece and Rome.

Nearly a thousand years after Rome's fall, Constantinople was conquered by the forces of Islam.

Barbarian kingdoms took possession of the fragments of the Roman Empire.

Charlemagne revived hopes for a new empire in Western Europe.

Amid invasion and civil disorder, a military aristocracy dominated the kingdoms of Europe.

Bishop, knight, and peasant exemplified some of the social divisions of the year 1000 A.D.

Famine, disease, and short life expectancies were the conditions that shaped medieval beliefs.

The great churches embodied the material and spiritual ambitions of the age.

Two hundred years of war and plague debilitated Europe.

A new urban middle class emerged, while dynastic marriages established centralized monarchies.

Renaissance humanists made man "the measure of all things." Europe was possessed by a new passion for knowledge.

The discovery of America challenged Europe.

Voiced by Martin Luther, Protestantism shattered the unity of the Catholic Church.

As the cities grew, new middle-class mores had an impact on religious life.

For more than a century, the quarrels of Protestants and Catholics tore Europe apart.

Amid religious wars, a few cities learned that tolerance increased their prosperity.