Arms and Society in Antiquity 9ninety-day radius of action from his capital in Iran.^9 As a result, his
campaigning season was cut too short to win decisive victory. By
invading Greece the Persians had in fact exceeded the practical limit
of imperial expansion. Other empires in other parts of the earth con
formed to similar limits, except when no formidable enemy existed
beyond the imperial frontiers. In such cases comparatively modest
garrisons and peripherally mounted expeditionary forces (like the one
Xerxes took with him to Greece) might suffice to enforce and extend
sovereignty. This seems to have been the case, for example, in south
ern China during most phases of Chinese expansion beyond the
Yangtse. When, however, the Chinese encountered effective local
resistance, their armies met the same fate as Xerxes’ did in Greece.
Vietnam owes its historical independence to this fact.
Transport and provisioning were, therefore, the principal limits an
cient rulers and armies confronted. The supply of metal and
weaponry, though important, was seldom a critical variable; and the
industrial aspect of warfare remained correspondingly trivial. Never
theless, one can detect in the historic record a series of important
changes in weapons-systems resulting from sporadic technical discov
eries and inventions that sufficed to change preexisting conditions of
warfare and army organization. Far-reaching social and political up
heavals accompanied such changes, as one would expect; and the
clutter of ancient dynastic and imperial history achieves a modicum of
intelligibility when the rise and fall of empires is viewed within the
framework of systematic changes in the military basis of political
power.^10
The first such horizon point has already been mentioned: the intro
duction of bronze weapons and armor at or near the very beginning of
civilized history, starting in Mesopotamia about 3500 B.C. Before im
perial command structures of the sort that Xerxes had at his disposal
became firmly rooted in ancient Mesopotamia, the next important
weapons-system change occurred. This was the result of radical im
provements in the design of war chariots. Mobility and firepower were
raised to a new level with the invention, soon after 1800 B.C., of light
- Conclusive proof of Xerxes’ time of march is unattainable, but cf. the careful
discussion of what a century or more of scholarship has been able to surmise in Hignett,
Xerxes’ Invasion of Greece, app. 14, “The Chronology of the Invasion,” pp. 448–57.
Herodotus tells us that Xerxes’ army took three months to go from the Hellespont to
Athens (8.51.1). - The points raised in the balance of this chapter are more extensively discussed in
William H. McNeill, The Rise of the West: A History of the Human Community (Chicago,
1963).