Arms and Society in Antiquity 17pected to arise, at least for a while, until the new rulers lost their tribal
cohesion and surrendered their warlike habits for the comforts of
urban living—in which case, renewal of the cycle of raid and conquest
was likely to take place.
A second pattern also asserted its power over steppe populations.
Both temperature and precipitation diminished from west to east
across the steppe. In Mongolia climatic conditions of the grasslands
became harsh for humans and animals alike. Eastward in Manchuria,
increasing rainfall brought richer pastures and temperatures became a
little milder. The result of this geographical layout was that tribesmen,
given a choice, preferred to leave Mongolia, pushing towards better
pasture by moving either east or west. The Scythians, presumably,
were responding to the superior attractions of the western steppelands
when they moved from the Altai to the Ukraine in the eighth century
B.C. Others followed them in succeeding centuries, bringing first
speakers of Indo-European tongues, then Turks, and finally Mongols
into eastern Europe, each people obeying the dictates of the geo
graphic gradient of the Eurasian steppe.
Thus two currents of population displacement resulted from the
cavalry revolution. Sporadically, steppe tribesmen succeeded in con
quering one or another of the civilized lands that abutted on the
grasslands—China, the Middle East, or Europe as the case might be.
This movement from pasture land to cultivated land coexisted with an
east-west current of migration within the steppelands proper. In the
one case, nomads had to surrender their established way of life by
becoming landlords and rulers of civilized countrysides. In the other,
the familiar nomad patterns could persist under somewhat eased con
ditions. Efforts by civilized rulers and armies to hold back the nomad
pressure were only sporadically successful. Even the Great Wall of
China was ineffective in stopping raids and conquest.
Geographical and sociopolitical conditions maintained a fluctuating
equilibrium between grassland and farmland. Insufficient rainfall
made farming in much of the steppe impractical. To be sure, in the
better-watered regions, like the Ukraine, grain farming was very re
warding, since wheat, too, is a kind of grass. In that region, accord
ingly, and in similar regions in Manchuria, in Asia Minor, and in Syria,
nomad occupation of natural grassland competed with grain farming as
alternative ways of exploiting the soil. Nomad warriors who decided
to remain as permanent occupants of these marginal farmlands often
drove plowing peasants entirely from the scene; yet the greater food-
producing capacity of a landscape that was farmed meant that time