One could argue that the Roman Empire collapsed under its own weight: It had become too vast to be effectively controlled by any one ruler.

By the close of the Punic Wars in 146 B.C., Greece, Macedonia, and the Mediterranean coasts of Spain and Africa had been brought under Roman control. Within a century, Rome again began to expand overseas. Under the Roman general Pompey (106–48 B.C.), eastern Asia Minor, Syria, and Judea (Palestine) were conquered. Next, Gaul was conquered by Pompey’s rival, Julius Caesar (100–44 B.C.), adding the territory west of Europe’s Rhine River to the Roman world. In 31 B.C., in the Battle of Actium, Octavian (63 B.C.-A.D.14; Julius Caesar’s adopted son and heir) defeated the forces of Marc Antony (c. 83–30 B.C.) and Cleopatra (69–30 B.C.), queen of Egypt, and in 30 B.C. Egypt became a Roman province.

In 27 B.C. Octavian became the first Roman emperor and was known as Augustus, meaning “exalted.” Though Octavian’s rule marked the beginning of the long period of stability called the Pax Romana, the Roman Empire had become so large—stretching across Europe and parts of Africa and the Middle East—that only a strong, central authority could govern it. During the 200 years of the Pax Romana, Rome’s emperors gradually grew more powerful, to the point that after death an emperor was worshiped by the people.

But soon there were threats to this central control, not the least of which was the spread of Christianity, as well as invasions from the Germanic Goths and the Persians. Theodosius I (379–395) was the last emperor to rule the entire Roman Empire. When he died in A.D. 395, the empire was split into the West Roman Empire and the East Roman Empire, setting the stage for the decline of the Romans.

The West Roman Empire came under a series of attacks by various Germanic tribes including the Vandals and the Visigoths (the western division of the Goths), who invaded Spain, Gaul (in western Europe), and northern Africa. These assaults eventually led to the disintegration of the West Roman Empire by 476.

The East Roman Empire remained more or less intact, but it became known as the Byzantine Empire and was predominately a Greek-oriented culture from 476 until 1453, when it fell to the Turks.