Makers of Ancient Strategy: From the Persian Wars to the Fall of Rome (49 page)

Danube frontier. The Huns’ second move, onto the Great Hungarian

Plain, was preceded by another huge exodus of Roman clients from

precisely that region: another large Gothic group led by a certain Rada-

gaisus, who moved into Italy, a large coalition comprising two separate

groups of Vandals together with Alans and Sueves, who moved across

the Rhine, and a further force of Burgundians, who followed them

in the same direction. The sources are not explicit that Huns caused

this second exodus. But Huns appear in the region vacated by these

migrants immediately afterward, and the most likely explanation for

this unprecedented demographic upheaval is that it was a repeat of

the scenario of the 370s, but this time played out across Rome’s Middle

Danubian and Upper Rhine frontiers as the Huns moved westward.32

In effect, the Huns imparted a unity of purpose among many tens of

thousands of invaders that is hard to imagine occurring otherwise. And

it was the simultaneous appearance of these politically separate barbar-

ian groupings that prevented the Roman Empire from defeating them:

as it attempted to do, and as it certainly would have been able to do had

not so many come at one time.33

The scale of the resulting strategic disaster was made much worse

from the Roman point of view by the fact that the empire’s attempted

military counterstrikes prompted a further phase of alliance build-

ing among the migrants. Thus, from half a dozen or so separate units

that entered the empire in 376–80 and 405–8, there emerged two much

larger units. The Visigoths, who eventually settled in southern Gaul in

418, were composed of the Tervingi and Greuthungi of the first phase,

united further with surviving Goths from the attack of Radagaisus on

Italy in the second phase. The Vandal force that eventually seized the

economically vital lands of North Africa, breadbasket of the western

empire, in the 430s (after a lengthy interlude in Spain) were likewise cre-

ated by the full unification there of both Vandal groups and the Alans,

who originally outnumbered them.34 The crucial point is that these

further political reconfigurations created groups big enough to resist

even major Roman field armies. Hence the new groups were able to

survive on Roman soil in the long term, not least because the intrusive

Huns united several of the other frontier Germanic groups under their

Frontier Defense 239

control beyond the frontier and began to mount campaigns, which

meant that the maximum Roman force could not be deployed against

the original—now reorganized—migrants.35 And while the Hunnic

Empire proved only a ramshackle and temporary phenomenon, its col-

lapse only increased the problems facing the imperial authorities, as it

led several other Germanic groups comparable in scale to the Visigothic

and Vandal alliances, not least the Burgundians and Ostrogoths, to end

up on western Roman soil as well.

The overall threat to imperial survival posed by these unsubdued im-

migrants was straightforward. The Roman state funded its armies and

other state activities overwhelmingly from a land tax on agricultural

production. When the newly enlarged barbarian coalitions formed on

Roman territory and proved impossible to dismantle, they ate away at

this tax base by seizing control of provinces, with or without imperial

consent. The Visigoths, for instance, were originally settled in limited

areas of southern Gaul (as were the Burgundians) with imperial con-

sent, while the Vandals seized the richest provinces of North Africa

by force. These annexed areas then paid nothing further into imperial

coffers. At the same time, imperial consent to these settlements was

always extracted at sword point, which meant that substantial tracts of

the land that did remain in imperial hands suffered considerable dam-

age and were consequently much less able to pay their customary tax

dues. Emperors customarily seemed to have granted damaged areas

a tax remission of six-sevenths. Very quickly, therefore, these barbar-

ian settlements pushed the central authorities of the western imperial

state into a vicious cycle of decline. Losses of land and revenue un-

dermined the capacity of the state to maintain its armed forces and

hence its capacity to resist the further demands of barbarian intruders,

whether those already on Roman soil or new ones from outside. Even

the Visigoths, erstwhile imperial allies, were quick to take any oppor-

tunity to expand their own area of domination, notably under Euric,

who launched wars of conquest after 468 that brought most of Spain

and much of Gaul under Gothic rule. As this process worked itself out,

both Romans and barbarians eventually came to realize that the central

Roman state was no longer the major player in the politics of Western

Europe, and it is no accident that the final act of imperial dissolution,

240 Heather

the deposition of the last western emperor Romulus Augustulus, oc-

curred when the wage bill of the remaining Roman army of Italy could

no longer be paid.36

The relevance of this story to the modern world turns immediately

on the process of imperial collapse. The developed Western world has

a marked tendency to see strategic problems in terms of its own poli-

cies, of what it has or has not done or might do in the future, as if other

parties to any relationship do not have a say in the ultimate train of

events. A similar kind of attitude is apparent in traditional approaches

to Roman imperial collapse, which largely focus on whether Roman

frontier strategies were wise enough or sufficient to combat the out-

side threat. An overall picture of developing patterns of political, social,

and economic organization in Central Europe of the Roman period,

however, emphasizes that it is just as important to focus on what the

so-called barbarians were doing. So often historians, usually following

Roman commentators themselves, have discussed the ultimate fate of

the frontier in terms of whether Rome, at different points in its his-

tory, found or lost the magic strategic calculus, when in reality, given

developing conditions on the ground, the empire’s fate was substan-

tially contingent on what was happening across the frontier. Rome was

at heart a Mediterranean-based empire that used those resources to

exercise domination over large parts of more northerly Europe. The

ultimate reason why the empire fell, and why a Mediterranean-based

state has never been so dominant in Western Eurasian history since,

lies in the fact that the first millennium marks a crucial watershed in

the development of Europe as a whole. New farming techniques gen-

erated much larger populations, which were then mobilized by much

more sophisticated political structures. The result was a fundamental

shift in the strategic balance of power, which meant that Mediterra-

nean resources no longer provided a sufficient power base from which

to exercise European domination. The accident of Hunnic intrusion

may have dictated exactly how and when the empire fell, but it was the

unleashing of forces of development in barbarian Europe that meant

that it was bound to fall sometime, and, what’s more, never return.

Perhaps even more important, I suspect, is what this story has to tell

us about the dynamic forces unleashed when originally less-developed

Frontier Defense 241

economies and political structures come into contact—on a whole

series of levels—with larger-scale imperial neighbors. For much of

the transformation that generated larger and more powerful socio-

economic and political structures on the fringes of the Roman world

in the first half of the first millennium AD can be traced to the con-

sequences of unprecedented contacts between barbarian and imperial

Europe: military, economic, political, and indeed cultural. Again, this

is not just a story of the empire doing things but of barbarians react-

ing with intelligence and determination to the opportunities and dan-

gers that imperial policies presented. In fact, the development of the

Germanic world is only one example of a much more general phe-

nomenon. In response both to the positive opportunities such contacts

presented and to the negative factor of aggressive exploitation that em-

pires generally exercise over their originally weaker neighbors, such

societies often display a marked tendency to develop and reorganize

themselves in such a way as to overturn the original inequalities of

power. Highly analogous patterns of development, for instance, are

visible among Slavic societies on the fringes of Frankish imperial Eu-

rope in the second half of the millennium.37 And this pattern, I would

argue, has held good to a considerable extent in more modern contexts

too, where the developed West’s economic, political, and even military

domination, so evident across the globe in the twentieth century, is

rapidly being overturned by outside political structures—modern bar-

barians, if you will—that it previously exploited but that have taken full

advantage of its dangers and opportunities to reorganize themselves.

What all of these examples suggest to me, in short, is that there often

operates a kind of Newton’s Third Law of Empires. The exercise of im-

perial political dominance and economic exploitation will in the long

run stimulate a series of reactions that turns initially weaker neighbors

into societies much more capable of resisting or even overturning the

aggressive imperialism that set those reactions in train.

Further Reading

The most important single work on Roman frontier defense continues to be Edward N.

Luttwak,
The Grand Strategy of the Roman Empire from the First Century a.d. to the Third

242 Heather

(Baltimore: Johns Hopkins University Press, 1976). Luttwak is not an ancient historian

but a strategic analyst who applied his expertise to the archaeological evidence of

Roman frontier fortifications and troop deployments. His cogent analysis—suggest-

ing that the empire moved deliberately from attack to defense in depth at the end of

the second century AD—set the agenda for all subsequent work, even if its conclu-

sions have been substantially modified. Three works among other notable titles—J. C.

Mann, “Power, Force and the Frontiers of the Empire,”
Journal of Roman Studies
69

(1979): 175–83, C. R. Whittaker,
Frontiers of the Roman Empire: A Social and Economic Study

(Baltimore: Johns Hopkins University Press, 1994), and B. Isaac,
The Limits of Empire:

The Roman Army in the East
, 2nd rev. ed. (Oxford: Oxford University Press, 1993)—have

among them shown that internal political agendas often adversely affected the work-

ing of truly rational foreign policy, and that command and control limitations made it

extremely unlikely that emperors were capable of the kind of strategic overview that

Luttwak’s hypotheses require.

Whittaker’s work has also contributed to a second critique, along with sustained

archaeological investigations conveniently summarized in such studies as L. Hedeager,

“The Evolution of Germanic Society 1–400 AD,” in
First Millennium Papers: Western Eu-

rope in the First Millennium
, ed. R. F. Jones, J.H.F. Bloehmers, S. L. Dyson, and M. Biddle,

129–44, B.A.R. International Series 401 (Oxford, 1988), and Maureen Carroll,
Romans,

Celts and Germans: The German Provinces of Rome
(Stroud, UK, 2001). These works have

demonstrated the extent to which the world beyond the frontier was transformed by

sustained economic interaction with the empire. My own work, particularly “The Late

Roman Art of Client Management and the Grand Strategy Debate,” in
The Transforma-

tion of Frontiers from Late Antiquity to the Carolingians: Proceedings of the Second Plenary

Conference, European Science Foundation Transformation of the Roman World Project,
ed.

Walter Pohl, Ian N. Wood, and Helmut Reinitz, 15–68 (Leiden: Brill, 2000), has drawn

on historical evidence (little explored by Luttwak) to show both that Rome did not in

fact move onto the defensive, as he supposed, and that Roman military and diplomatic

activities, in conjunction with economic interactions, played a major role in creating

larger and more coherent political structures in neighboring barbarian societies. For

the argument that it was this transformation of the north and east that eventually

made it impossible for a Mediterranean-based state to extend a Europe-wide domina-

tion, see now Peter J. Heather,
Empires and Barbarians: Migration, Development and the

Creation of Europe
(London: Macmillan, 2009).

Notes

1 Edward N. Luttwak,
The Grand Strategy of the Roman Empire from the First Century

a.d. to the Third
(Baltimore: Johns Hopkins University Press, 1976).