During the fi rst and second centuries b.c.e. Rome ex-
panded into the region known as Gaul, which corresponds
roughly with modern-day France and a portion of northern
Italy. Gaul, like Italy, was a collection of smaller regions. Rome
subdued the region called Narbonensis, along the southern
coast of Gaul, in about 120 b.c.e. Later conquests included
Cisalpine Gaul (in today’s northern Italy) in 81 b.c.e., Aqui-
tania (a large region along the western coast) from 56 to 51
b.c.e., Lugdunensis (also a large region extending from the
northwest coast into central Gaul) from 58 to 51 b.c.e., Bel-
gica (corresponding to modern-day Belgium) from 57 to 51
b.c.e., and regions of Germania (Germany) in 17 c.e. Also,
in 29 b.c.e. the Roman emperor Octavian conquered Egypt.
Again, these conquests led to the migration of Roman people
throughout the Mediterranean region.
THE ROMAN EMPIRE
Although these conquests and expansions suggest an “em-
pire,” historians refer to the period up to 27 b.c.e. as the Ro-
man Republic. Th ey use the term Roman Empire to refer to
the period from 27 b.c.e., when the emperor Octavian im-
posed his vision of government on the Roman Senate, to 476
c.e., the end of the empire in western Europe.
Further expansion of the Roman Empire took place into
the second century c.e.; the most important event was the
conquest of Britain in 43 c.e. Th us, by the second century
of the Common Era the Roman Empire essentially encircled
the area around the Mediterranean Sea and extended as far
north as the British Isles. To the west and north it encom-
passed Britain, Spain, portions of modern-day Germany, and
all of Gaul; the northern border of the empire was marked
by the Rhine and Danube rivers, where such northern Eu-
ropean tribes as the Huns, the Vandals, and the Visigoths
massed until they spilled southward and eventually defeated
the Romans. Until then, though, these rivers were major bar-
riers to the movement of populations. Th e empire extended
eastward from Italy into Greece, Asia Minor, and such areas
as Cappadocia, Armenia, Assyria, and Mesopotamia, then
south through Palestine into Egypt. To the south the empire
included a wide strip of northern Africa.
Rome’s most diffi cult province was probably Britain.
Over three centuries of rule the Romans met with frequent
resistance, not only in modern-day England but in Scotland
and especially in Wales. During these centuries numerous
bodies of troops had to be dispatched to Britain to quell up-
risings led by local leaders. Th e result was a two-tiered ad-
ministration, with peaceful areas under the control of the
Roman Senate but areas of resistance under the emperor and
his troops. Th e areas were controlled by resident governors
whose role was primarily military but included keeping up
diplomatic relationships with local kings, building roads,
supervising cities and their surrounding areas, recruiting
troops, collecting taxes, and administering the law. Th e gov-
ernor also supervised a large number of managers whose job
was to gather intelligence about the activities of local kings
and their followers, communicate with Rome, order and store
military supplies, take charge of prisoners, and perform simi-
lar administrative functions.
Determining the population of the Roman Empire is
almost impossible, given the lack of accurate records. Also,
what records do exist remain unclear about who precisely was
counted. Th e best historians can do is off er a range of likely
estimates and arrive at a consensus. It is estimated that in 1
c.e. the Roman Empire comprised about 45 million people,
out of a world population of 200 to 300 million. Other his-
torians use a fi gure of about 55 to 60 million. Conservative
estimates put the number at about 65 million by the second
century c.e., but some historians argue that the number was
much greater, perhaps as many as 130 million, or some 40
percent of the world’s total population.
Using the lower estimate, historians have concluded that
among the population were 600 senators, the top tier of Ro-
man society. Below the senators were some 30,000 equestri-
ans, or knights. Th e military consisted of some half a million
soldiers, many of whom were stationed along the empire’s
frontiers and included not only Romans but locally con-
scripted mercenaries. Between 10 percent and 30 percent of
the population, or six to nine million people, occupied cit-
ies, including one million in Rome. (By the sixth century
wars and plague had reduced the population of Rome to just
30,000 to 100,000 people, and it would take 1,500 years for
a European city again to reach a population of one million).
Finally, historians estimate that the slave population of the
empire, imported from throughout the empire typically as
a consequence of military conquest, totaled anywhere from
two to 10 million, with half a million living in and around
Rome itself.THE ROLE OF ROADS
Roads and road-building technology played a major role in
the expansion of the Roman Empire and the movement of
peoples. Such a vast empire required means of travel to ac-
commodate military troops, trade, and communications and
to allow large numbers of administrators, civil servants, and
other offi cials to move freely about the empire. Th e colloquial
expression “all roads lead to Rome” was in fact true. At the
center of the road system was the Forum, the earliest site in
ancient Rome. From that central point a traveler could get to
virtually any place in the empire on 50,000 miles of paved
roads, some of which are still in use in the 21st century. In
large part because of the road system, large numbers of Ro-
mans could move from the empire’s capital to the most far-
fl ung areas of the empire, taking with them all the elements
of their culture: the monetary system, art, administration,
military tactics and technology, engineering, roads, water
and waste management systems, government, and so on.
Roman roads were more than just tracks through the
woods. Th e roads were built in much the same way as modern
roads are, with fi rm underlays capped by paving stones. One
innovation the Romans developed was that of the crowned716 migration and population movements: Rome