by John Keegan
Greek helmet and cuirass of the Eighth Century BC, the oldest discovered suit of hoplite armour. Bronze was preferred for bodily protection long after it was supplanted by iron in the manufacture of weapons.
A hoplite of the Sixth Century BC his shield has not yet assumed the distinctive bowl shape, in which the wounded — or dead — warrior was brought back from the battlefield.
Hoplites preparing for battle, from a vase painting of 515 BC; the shield protected the stomach and thighs from spear thrusts when the massed ranks closed.
A Roman oared warship, descendant of the Greek trireme, advancing to battle; its prow is armed with a ram and its upper deck manned by marines.
Legionaries crossing a bridge of boats, from Trajan’s Column, Second Century AD; the Legions, like the Assyrian army, marched with a bridging train on campaign.
A centurion of the XX Legion, one of the four which conquered Britain, who died at Colchester about 45 AD. He carries his vinestick of authority.
Terracotta of a barbarian enemy of Rome from the Puy-de-Dôme, Third Century AD; a forerunner of the tribesmen who overwhelmed the empire in the Fifth Century.
A Frankish horseman on his warhorse, in chain mail and with shield and lance as depicted by a Scandinavian enemy — who was unaware of the stirrup — in the Eighth Century.
Crusaders in chain mail charging Muslim horsemen, Fourteenth Century; in practice, Middle Eastern light horsemen avoided the direct clash of arms.
A late Fifteenth-Century depiction of escalade at the siege of a fortified city; the soldiers wear plate armour but there are cannon in the entrenchments.
The earliest known representation of a cannon, 1326; the gingerly application of linstock to touchhole indicates how unfamiliar the weapon was.
The beginnings of mutuality between man and the gunpowder weapon, about 1400; a century later the soldier would be putting it to his shoulder.
Galleys of the Knights of Malta (the Hospitallers of the Crusades) in battle with the Ottoman fleet, early Seventeenth Century; land warfare at sea.
The Great Harry, one of the first ships built — for Henry VIII of England in 1514 — to fire cannon broadside; they would dominate naval warfare until the 1850s.
A Seventeenth-Century manual of arms; step-by-step procedure in the handling of the musket by ranked men was essential to avoid fatal accidents.
Siege cannon, hitched to limbers drawn by trains of horses, on the way to a position, 1702; cannon such as these inaugurated the artillery revolution two hundred years earlier.
A gunpowder mill, from The Universal Magazine, December, 1773; the monopolisation of gunpowder production by governments was a key to the rise of the modern state.
The battle of Williamsburg, May 5, 1862, American Civil War; despite the North’s material superiority. Southern musketry and digging saved Richmond in this Peninsula Campaign.
Cannon manufacture in the American Civil War; the Americans were the first industrial nation to apply mass-production methods in arsenals.
Northern railroad soldiers at work on the Orange and Alexandria line during the American Civil War; railroad construction — and destruction — underlay the North’s victory.
Alfred Krupp’s trial range at Meppen, 1879; his steel cannon revolutionised artillery equipment in the years before the First World War.
A British trench sentry on the Somme, 1916, with sleeping comrades; even routine trench warfare was dangerous and exhausting.
A German Junkers 87 dive-bomber launches its bomb at a French tank during the blitzkrieg of 1940, a portent of the air domination of the battlefield.
An Atlantic convoy bringing war supplies from America to Britain, 1943; the escorting aircraft was the instrument of the U-boats’ defeat.
Flying Fortresses (B-17s) in the strategic air campaign against Germany, 1944; the condensation trails are from their escorting fighters.
Test explosion of an atomic bomb at Bikini atoll, July 25, 1946; no military thinker has explained how nuclear warfare might be a continuation of politics.
The Roman empire was now almost as large as it would ever be in the west and had achieved nearly its fullest extent in Africa and the Near East; only on the frontier with the Middle East, where the kingdoms of Parthia and Persia were still powerful enough to contest control with Rome, would there be conquests still to be made. The very success of imperial expansion had thrown the social and political order at home into crisis, however. The relentless search for recruits, particularly among the Italians to whom incorporation in Roman territory had not brought the privileges of citizenship, and the growing power of consuls returning victorious from their annual campaigns to confront the magistrates in Rome with demands for money and authority, rendered the old systems of legionary enlistment and elective government increasingly obsolete. There had been a foretaste of trouble at the end of the second century BC when the brothers Gracchus had attempted to reduce both the burden of the military levy and the independence of the military authorities. Trouble became serious in 90 BC, when the Italian non-citizens revolted against the levy and were pacified only by grant of full citizenship. The difficulties in supplying the legions with manpower nevertheless persisted, even though there had been an effective dispensation with the ancient property qualification at the end of the first century, when the consul Marius opened the ranks to volunteers from the lowest census class. This measure paradoxically heightened the developing conflict between campaigning consuls and the city’s political class, since it attached landless legionaries more closely to a commander, identified their interest with his (particularly if, as Marius did, he promised land as a reward for successful service) and thus strengthened the hand of generals against senate and magistrates.58
The crisis came to a head on Caesar’s completion of his Gallic conquests. When he sought to prolong his period in command, the senate refused him; when he left his province, outside which his powers of command legally lapsed, at the head of the XIII Legion to return to Rome, he effectively threw down a challenge to civil war. The war lasted seven years (50–44 BC) and was fought as far afield as Spain, Egypt and Africa, as the senate found legions and generals, notably Pompey, to resist Caesar’s rebellion. It culminated in his triumph and then, at the hands of principled opponents of dictatorship as well as disgruntled enemies, in his assassination. In the struggle for power that followed, Caesar’s nephew, Octavian, overcame all opponents in a renewal of the civil war and in 27 BC, having already been granted the title of Emperor (though nominally ‘Princeps’, first citizen) by a compliant senate, added to it that of Augustus. Republican forms, though preserved in name, were effectively extinguished from that moment and henceforth Rome was an empire in substance as well as extent.
The imperial system resolved the anomalies inherent in the attempt to govern a military state through the competitive politics of an exclusive and no longer representative electoral class. The first effects were felt in the army itself. Augustus found it grossly swollen by civil war, to a size of half a million men, many of them little better than mercenary followers of rival commanders; he sharply reduced its numbers and stabilised it at a strength of twenty-eight legions. To assure the security of the central government against a repetition of Caesarism, he formed a new force, the Praetorian Guard, to garrison Rome. The field army was distributed largely to the frontiers, with the heaviest concentrations on the lower Rhine, opposite Germany, from which population pressure was already felt; on the upper Danube, another region disturbed by the barbarians; and in Syria; smaller garrisons were maintained in Spain, Africa and Egypt. Equally important were the alterations he introduced into the basis of service. The fiction of the militia obligation was abolished and the legions became professional by enlistment. Preference was given to citizens, but suitable non-citizens were granted citizenship on recruitment; the term of service was fifteen years (often twenty in practice), during which legionaries were forbidden to marry — though families naturally, if illegally, attached
themselves to the camps; pay was fixed and regular and, on discharge, the veteran received a retirement gratuity sufficient to provide him with a living. New taxes, actuarially calculated, found the large sums necessary to settle the veterans and so to provide the serving soldiers with a consequent incentive to loyalty and good conduct.
The numbers in the Augustan army settled at about 125,000 men. A similar number served in the legions’ auxiliary units of cavalry and light infantry. Rome had employed such units since the start of the Italian conquests, but the auxiliaries had not been citizens and their terms of service had been irregular. Henceforth, certainly from the reign of Claudius, the successor of Augustus, they were properly paid, but the great inducement was that, at the end of twenty-five years’ service, the discharged soldier received a grant of citizenship; so, too, since he was allowed to marry, did the sons of one wife, whenever born. These provisions greatly improved the quality of auxiliary troops, some of which were to perform so well that their members would be granted citizenship en bloc. As time went on, moreover, the cavalry wings and infantry cohorts ceased to be recruited at the point of service (a tendency that assimilated their quality much nearer to that of the legions), passed from the command of local chiefs to imperial officers, and were posted for duty anywhere in the empire.59
Augustus did most to secure the future reliability of the army by the arrangements he made for its command. Under the republic the proconsul of a province had commanded the legions within it. Augustus appointed himself proconsul of most of the provinces, so that he directly commanded their legionary garrisons, while decreeing that for the rest, to which the senate still appointed its nominees to govern, the legions came under his command also, through legates who were his personal representatives. To administer and finance this complex and highly centralised system, Augustus created an imperial civil service, staffed at its head by members of the political class, for whom it provided welcome responsibilities as well as state salaries. To these imperial officers fell the duty of raising taxes to support the provincial administrations and garrisons, to make the transfers to the imperial treasury and, in Egypt and Africa, to buy and collect the grain which supplied the city’s families with free rations; 400,000 tons were imported each year.
This Julio-Claudian system, as historians call it, served well under his immediate successors, but contained unperceived perils. With a disputed imperial succession, or defeat in war, authority tended to revert to the army, on which the whole structure rested. The Roman empire’s success committed it inevitably to go to war, since it could not tolerate disorder on its borders, while the growing prosperity it fostered encouraged envious outsiders to seek entry by force. Disorder was the principal danger in the east, where ancient kingdoms and the surviving rival empires of Parthia and Persia resented Rome’s efforts to establish a stable line of control; intrusion was the danger in the west, along the Rhine and Danube, where the great movements of population, impelled by pressures from the steppe, were already being felt during the first century AD.
In AD 69 the predictable crisis supervened. There had been military successes under the Julio-Claudians. Britain (invaded in AD 43) had been added to the empire and Armenia had in 63 accepted Roman suzerainty. Equally there had been revolts, notably in Germany, where Arminius had destroyed a Roman army in the Teutoburg forest (AD 9), and in Judaea, where the Jews rose against Roman rule in 66. In 68 the eccentric, perhaps mad, reigning emperor, Nero, lost his soldiers’ confidence and was overthrown by military insurrection; this led to civil war, competing claims to the succession and the eventual emergence of a soldier-emperor, Vespasian, not of Julio-Claudian birth. Able and cautious, he restored imperial stability but, as a military usurper, lacked legitimacy. That was revived by his eventual successor Nerva, who established the principle of appointing strong rulers by the process of formal adoption of a promising heir. Thus four adoptive successors, Trajan, Hadrian, Antoninus Pius and Marcus Aurelius, were all gifted administrators and successful commanders. Under these Antonine emperors (AD 98–180) the Roman armies won a string of victories and added Mesopotamia, Assyria and the trans-Danubian province of Dacia (modern Hungary) to the empire.
The success of the Antonines derived from their adoption of a policy of military stabilisation wherever it could be achieved, which meant everywhere except on the open border with Parthia and Persia. This has been called ‘a grand strategy based on preclusive security — the establishment of a linear barrier of perimeter defence around the Empire’.60 Historians differ bitterly over the complexities of the strategy. Some deny that it had any basis in Roman consciousness, and that the apparent drive to reach and hold ‘scientific’ frontiers, on the Rhine, Danube, north British highlands and edge of the Sahara, signified by the building of the fortifications whose sometimes massive relics still mark their outline, reveals nothing more than the desire of local commanders or visiting emperors to establish police posts and customs control at the edge of a zone of formal administration.61 Those who hold such views deserve attention, since their knowledge of the details of Roman military policy is extensive and exact; the strength of their views is also reinforced by the terms in which they characterise the Roman military outlook: always informed by ‘a desire for glory’ rather than by strategic theory. That perception rings true. Clausewitz and his contemporary ideologues may have been inspired by Roman military practice, but the notion that Roman warmaking, any more than Alexander’s, was Clausewitzian in essence bears very little weight. However logical his analysis of particular military situations, Alexander was drawn eastward by vainglorious impulse; Rome, perhaps also vainglorious, certainly entertained no conception of ‘war as the continuation of politics’ since it granted to none of its enemies, not even the Parthians or Persians, the dignity of civic status. Like the Chinese, the Romans divided the world into civilisation and the lands beyond its sway, and while they sometimes of necessity resorted to diplomacy (in their dealings with the Armenians and other old-established kingdoms, for example), they did so for reasons of expediency alone, not as one state treating with its equivalent. There was, indeed, no reason for them to do so. Not only by the tests of military and bureaucratic organisation did the Romans surpass every other people against whom their borders abutted. The ‘idea’ of Rome, which in AD 212 extended citizenship to all free men within its imperial boundaries, had no parallel elsewhere; nor did the extraordinary infrastructure of roads, bridges, aqueducts, dams, arsenals, barracks and public buildings by which Roman military power, civil administration and economic life were sustained.
Nevertheless, the existence of Rome’s fortified frontiers, like much of China’s Great Wall, is a fact. The Chinese learned that the building of a fixed line of defence does not of itself guarantee security, which can be maintained only by the simultaneous execution of a ‘forward’ policy, as by the T’ang into Dzungaria and the Manchu on to the steppe; the failure of the intervening dynasties of non-steppe origin to pursue or succeed in such a policy did not invalidate the building of the Wall in the first place, since it marked the outline of the cultural zone that all Chinese governments sought to preserve. Equally, the retrospective denials by some modern scholars that the Roman effort at fortification was a subordinate and secondary characteristic of the empire’s real strategic purposes stumbles on the stones of the fortifications themselves. It may well be that in the first two centuries after Augustus the empire depended on the strength of the legions, variously deployed, to sustain security by indirect means. That is the view of Edward Luttwak, who suggests that the policy of the Julio-Claudians, who were still fighting wars of expansion, was to use the legions as a source of ultimate guarantee for a defence organised in first line by newly subdued clients, such as those in northern Greece, Asia Minor and Africa; while under the Antonines the legions were distributed at the frontiers to garrison barriers which then became the primary obstacle zone on which external threats were intended to break. Particular crises, he argues, were met by the c
oncentration at the point of danger of legions withdrawn from borders where peace prevailed. His view is disputed by others who variously claim that the Romans remained expansionist on the frontiers where enemies challenged their power, notably those with Parthia and Persia, or that the army’s main preoccupation was with local disorders which had their roots in habits of endemic brigandage, piracy or the indisciplines of transhumant herding tribes.