became professionalized. Finally, the loyalty of the legions
became detached from the state and focused on the various
army commanders. Th is resulted in a period of intense civil
war lasting for about 20 years (49–31 b.c.e.) and led to the
establishment of a military monarchy.
Under the fi rst emperor Augustus (r. 27 b.c.e.–14 c.e.) the
army became completely professionalized, with service stand-
ing at 25 years. Th is professional army was stationed along the
distant frontiers of the empire. Th ere were now two types of
troops: the legionaries, who were Roman citizens, and the
auxiliaries, who were noncitizens but who could gain citizen-
ship at the end of their service. In addition to heavy infantry
that fought along with the legions, the auxiliaries provided
specialist troops such as archers and most of the cavalry. By 14
c.e. the army totaled 300,000 men divided among 25 legions
and an equal number of auxiliaries. Th e number of legions
increased until by 200 c.e. there were 33. Under the empire
for the fi rst time troops were stationed in the city of Rome, of
which the best known were the nine cohorts of the Praetorian
Guard, whose main tasks were to guard the emperor and to
keep the peace in the city. Th e emperor was closely tied to the
army, and its loyalty to him provided the basis of his power.
With the professionalization of the army came the pro-
fessionalization of training. During the Republic there was
no formal system of training either before entry or during
campaigns. A commander decided whether to train his
troops, and most soldiers seemed to have learned their weap-
ons skills on their own initiative. Under the empire a formal
training system was instituted within the army. Specialists
with military rank were employed to teach basic skills. Th ese
remained the same as they had been earlier; physical tough-
ening, marching in formation, care of equipment, and weap-
ons drill. Th is training was one of the keys to Roman military
success, as it instilled a level of discipline and expertise that
Rome’s enemies normally could not match.
Th e earliest Roman military fortifi cation was the march-
ing camp, which was constructed daily while the army was en
route. Th e basic fortifi cation consisted of three parts: a ditch,
an earthen wall inside of the ditch constructed of the dirt re-
moved from the ditch, and a wooden palisade built on top of the
wall from stakes carried by the legionaries. Th is was not meant
as a permanent fort but as temporary protection and was de-
stroyed as the army marched. Toward the end of the fi rst cen-
tury c.e. permanent stone fortresses replaced the earlier earth
and wood structures but kept their basic plan. Th is refl ected
the now-static positioning of the legions. Also in this period
separate stone forts for housing units of auxiliaries appeared.
At the same time much larger fortifi cations, such as Hadrian’s
Wa l l that separated the Roman province of Britain from un-
conquered Scotland, were built. In the third and fourth centu-
ries c.e. forts and other fortifi cations became more elaborate in
response to increased military threats. Stone was standard, and
towers and elaborate gate defenses were constructed.THE AMERICAS
BY J. J. GEORGE
An organized military, like other developed social institu-
tions, implies a sophisticated authority structure oft en attrib-
uted to advanced societies and is thus linked to the origin
of civilization. Nonstate entities typically show less military
organization than formal states and rely more on a warrior
culture in which every male in society is a serviceable militia
member. Arguably, military institutions may be necessary for
the transition to state organization and civilized life. What-
ever their causal role, military institutions lie very close to the
core of civilizations as they have developed. In the Americas
fully developed militaries recognizable to modern eyes—
state-supported institutions operating in an occurrence of
violence to pursue political goals—emerged only toward the
end of the ancient period, while earlier military practice took
rudimentary but recognizable forms.
Th e earliest American military institutions probably de-
veloped around 1000 b.c.e. among the Olmec in Mexico’s Gulf
Coast region. Th e Olmec, an early state or semistate, intro-
duced specialized weaponry, such as maces, exclusive to war-
ring as they pursued expansion. Taking prisoners was tied toMarble statue of a youth on horseback and wearing a military cloak,
Roman, made in Italy (ca. 1–50 c.e.) (© Th e Trustees of the British
Museum)
Military: The Americas 735