A History of Warfare

by John Keegan

  Philip’s eighteen-year-old son, Alexander, had been present at Chaeronea, where he led the cavalry of the left wing in what proved the day’s decisive stroke. Two years later he was king himself; whether or not he was party to the conspiracy through which Philip met his death tantalises his biographers to this day. No breach in Macedonian policy followed from the succession. Indeed, Alexander took up the challenge of a Persian ‘crusade’ even more energetically than his father had promised to do. Having conclusively subdued Philip’s old enemies on Macedon’s northern border, and put down a resurgence of Theban defiance, he marshalled the Macedonian army, strongly reinforced with mercenary contingents recruited from the surplus of soldiers left unemployed by the Greek wars, crossed to Asia in the spring of 334 and set out to topple Darius III, the ruling Persian emperor. It was an undertaking of breathtaking audacity. Persia had made itself master of the lands of all previous Middle Eastern empires and its boundaries extended to enclose not only Persia proper but Mesopotamia, Egypt, Syria and Asia Minor with its Greek colonies. The Persian army, though still centred on a chariot nucleus, included heavy cavalry forces and large numbers of Greek mercenary infantry.

  Alexander’s own army mirrored in organisation that of the Persians. Though it had no chariots, which had long fallen out of fashion in Greece, it included regiments of heavy cavalry, mounted on horses bred on the grasslands beyond the Macedonian mountains; his own shock force of Companions, horsemen (still without stirrups and riding rudimentary saddles) who wore armour and wielded spear and sword; and a powerful phalanx core, whose soldiers wore the traditional Greek body-armour but carried an even longer spear, the sarissa, so allowing the phalanx to be ranked at twice the depth of the old. Its component units were formed on a tribal basis but, more important, the Macedonian element was informed by a strong national spirit, while Alexander achieved remarkable success in implanting a sense of common patriotism among the Greeks he took to Persia with him. Altogether his soldiers numbered some 50,000 — this was enormous compared to the numbers who had opposed each other in the largest campaigns of the Peloponnesian War, when Sparta rarely found more than 10,000 troops — of which most were infantry.39

  Alexander campaigned in Asia for twelve years, and his restless spirit eventually carried him as far away as the plains of northern India in search of new conquests. The decisive strokes against Persia were laid early on, however, in the three battles of the River Granicus (334), Issus (333), and Gaugamela (331), which progressively destroyed the Persian imperial army’s capacity to resist and eventually overwhelmed it. The Granicus was a preliminary engagement, chiefly remarkable for the dynamic leadership displayed by Alexander at the head of his cavalry. ‘It was a cavalry struggle,’ wrote his biographer, Arrian, ‘though on infantry lines; horse pressed against horse … trying to push the Persians from the brink and force them onto level ground, the Persians trying to bar their landing and hurl them back onto the river.’40 Alexander chose his point of attack by observing how the Persians had sought protection behind the river banks, clear evidence of faint-heartedness and an interestingly ‘primitive’ survival of evasive tactics, which we know continued to permeate the ethos of Middle Eastern armies for another millennium. Alexander’s Greek impatience with anything but face-to-face fighting impelled him to charge where the Persians looked strongest, a risk proved exactly justifiable when they broke before him. The Greek mercenary phalanx in second line, ‘rooted to the spot by the unexpected catastrophe’, was surrounded and hacked down.41 Alexander himself was wounded, but in the totality of his victory that was forgotten. He had demonstrated that a Greek phalanx, combined with armoured cavalry, could carry war into Persian territory and press home its advantage. At Issus in the following year he reinforced the point. Outnumbered three to one (if the best estimate that Darius, who was present in person, had 160,000 men under command is correct), Alexander once again chose to attack on the strongest sector, picked out for him because ‘in some parts [the Persians] had built up palisades [so that] Alexander’s staff perceived Darius to be a man of no spirit’.42 Crossing the enemy’s missile zone at speed, and so braving what ought to have been a disabling barrage from the arrows of the Persian composite bowmen, he led the cavalry directly against the flank where Darius stood. In the centre his phalanx collided and was stopped by its Greek mercenary equivalent, but, after putting Darius to flight, he turned his horsemen to roll up the enemy infantry’s flank and complete the victory.

  The third confrontation was delayed while Alexander invaded and occupied those sections of the Persian empire — Syria, Egypt and northern Mesopotamia — that Darius had by now abandoned. It was not until twenty-three months after Issus that Alexander ran the Persian army to ground again, at Gaugamela, on 1 October 331 BC. The Macedonians were now at what seemed to be the extreme limit of their logistic outreach, having left their supporting fleet far behind by crossing the Euphrates to enter Mesopotamia proper. Darius calculated that, could he hold Alexander on a strong position, the Macedonians would either be defeated there or might disintegrate as an army if forced into retreat. He made his position at Gaugamela very strong, clearing an area on a tributary of the Tigris eight miles square, to give his chariots — which may have had scythed wheels — unimpeded room for manoeuvre, and making three parallel avenues down which they were to charge (the Chinese, as we have seen, also believed in thus preparing a battlefield). His army included not only charioteers (he himself paraded in a chariot, in continuation of the Middle Eastern imperial tradition) but contingents from twenty-four different subject or mercenary nationalities, among which were a few remaining Greeks, Scythian horsemen from the steppe, some Indian cavalry and even a group of elephants. As at the Granicus and Issus it outnumbered the Macedonian army considerably — there were at least 40,000 Persian cavalrymen present — and stood on well protected ground of its own choosing.43 Success looked assured, and might have followed, had Alexander not first played Darius at his waiting-game and then effected an altogether novel tactical stroke. He delayed advancing to action for four days, leaving the Persians idle in their positions; when he eventually did so, he matched his deployment to that of Darius, cavalry on the wings and infantry in the centre, but then, in a creative adaptation of Epaminondas’s manoeuvre at Leuctra, led it across the face of the Persian line to menace the enemy’s left flank. Surprised, the Persians delayed counter-charging until the Macedonians had made contact; when at last they charged, Alexander was close enough up with his Companion cavalry to lead it into the gap thus created and panic Darius, who stood immediately in Alexander’s path, into headlong flight.

  It was not until ten months later that Alexander caught up with the emperor, then to find him dead from wounds just inflicted by his cowardly courtiers. Alexander, who had already proclaimed himself both Pharaoh of Egypt and King of Babylon, and had already taken the title of Persian emperor, now began to call himself King of Asia. At home, where outbursts by the ever-dissident Spartans and Athenians had been crushed, the Greek League had reaffirmed his appointment as overlord for life; he now set forth to make good his claim. He had already assessed the courses of action open to him:

  [to] withdraw to the Euphrates lines, leaving the military and economic strength of Persia broken; [to] stop, as Trajan was to do later, content with control of the rich plains of Mesopotamia; or [to] go on to conquer the rest of the Persian empire. Alexander took the third course. For the Persian empire resembled Macedonia herself, in that its rich plains were exposed to the attacks of the vigorous mountain peoples of the north and its further provinces formed a barrier against pugnacious nomadic peoples.

  In short, Alexander had unwittingly inherited the strategic problems of those earlier valley emperors of whom he was now the successor, problems indeed that were replicated in China’s relationship with the peoples north of the great bend of the Yellow River, in Rome’s and Byzantium’s wars on their Asiatic borders and ultimately in Christian Europe’s efforts to define and hold its e
astern steppe frontier. Alexander appeared to solve his inherited difficulties by a brilliantly positive policy of driving his line of control ever eastward, thus allowing none of the potential invaders into the Persian heartland to hold a footing from which attacks could be launched. In truth, however, his long military wanderings through Central Asia and northern India were the pursuit of a chimera. A new enemy presented itself after each conclusive victory until his army, at last tiring of exile, obliged him to turn for home. Behind he left a string of superficially Hellenised satellites that his generals ruled for themselves after his death at Babylon in 323 BC. But their foundations were insecure, their rulers fell to quarrelling among themselves, and during the following century most lapsed from Hellenism and reverted to their native state.

  Alexander had struck at a propitious moment. His principal target, Achaemenid Persia, had overextended its power and was vulnerable to attack at its periphery, particularly when, to oppose the ferocious face-to-face fighters of the Macedonian phalanx and Alexander’s armoured cavalrymen who, as Arrian perceptively remarked, fought like hoplites on horseback, it had to depend in bulk upon soldiers who belonged culturally to the Middle Eastern tradition of avoiding close combat, fighting behind a missile screen and trusting to obstacles to impede the enemy’s advance. It was fortunate for Alexander, too, that when he struck out into Central Asia after his conquest of the Persian heartland, he campaigned among societies that had not yet acquired the strengths they were to find in the next millennium from Islam and their accumulated experiences of successful horse warfare. Alexander’s life was indeed an epic; if his Byzantine successors, however, failed to repeat his successes in their struggle to sustain the frontiers of their empire to the Caucasus and the Nile, it was not because they lacked his will, capacity or resources, but because they were confronted by a far more formidable military problem.

  ROME: MOTHER HOUSE OF MODERN ARMIES

  The collapse of Alexandrian Hellenism in the East was matched at home also, though not through the quarrels of his successors. The power of the house of Macedon in its heartland, and over Greece also, was eventually overthrown by a people insignificant in Alexander’s time, the Romans. Rome owed much to Greece for its rise. In the sixth century BC it was little more than a village on the banks of a river, where three tribes bearing Etruscan names, evidence of the dominance of Etruria to the north, lived under the rule of a king. During the reign of Servius Tullius, 580–30 BC, the population was supposedly organised into five military classes drawn from the propertied, and a militia was founded which certainly practised hoplite tactics.44 The Romans later claimed that they took their tactics from the Etruscans, but it seems more probable that they were imported from the Greeks, probably those living in sizeable numbers in southern Italy. At about the same time a republican form of government replaced the monarchy, and it was under the republic that Rome first began to extend its area of control, initially by conflict with the Etruscans, themselves under pressure from the Gauls of northern Italy, then with the Gauls directly, finally with the Samnites to the south. When Rome’s southern expansion brought her into contact with the Greek colonies in Calabria and Apulia, in the third century BC, they sent for help to Pyrrhus, ruler of one of the Alexandrian successor kingdoms in Greece; though victorious, he was so shaken by the costs of fighting a Roman army, particularly in the battles of Ausculum (299) and Beneventum (295), that he abandoned the campaign.

  The Roman army had by now moved far in organisation from the hoplite model on which it was based. During their wars with the Gauls, who fought in a loose but dynamic open order, the Roman commanders had found that the tight ranks of the phalanx put their troops at a disadvantage. They had therefore introduced a system which allowed subsections, ‘maniples’ or handfuls, to manoeuvre on the battlefield and had progressively abandoned the thrusting spear in favour of a javelin, the pilum, which, when thrown, the soldier followed sword in hand. Increasingly, too, the soldiers of the legion, as the groups of maniples which constituted a division came to be called during the fourth century BC, dispensed with the heavy hoplite equipment; they adopted a light, oblong shield and, eventually, standard and much lighter body-armour of hooped iron, which would not have been proof against the pike-thrusts of phalanx fighting but served adequately to deflect sword-blows and missile-points. As important for the long-term efficiency of the Roman army as this change in equipment and tactics was the introduction of a new basis of service. Though by their frequent hiring of mercenaries the Greek city states had eventually compromised the principle that the citizen supported himself in the field, and while some were even driven to equip and pay their servicemen at public expense — by 440 Athens was paying its galley crews and overseas garrisons — the duty of the hoplite to campaign at his own expense remained an ideal.45 By the fourth century Rome had abandoned it, and was paying the legionaries a daily stipend. This development marked the most important divergence of the Roman from the Greek military system. Rome’s smallholders, at the dictate of an increasingly dominant political class, ceased to be attached to and supported by their land and became a recruiting pool for a professional army which campaigned, year after year, farther and farther from home, as the Roman republic extended to form an empire.46

  Rome’s imperial motives are much disputed by scholars. It was the traditional view, certainly one supported by Roman sources, that an economic motive lacked. Rome certainly did not need to find food for a growing population, as Athens did, since rich lands were easily annexed within a short campaigning distance of the city. On the other hand, Rome grew rich by conquest, and its empire’s expansion fed on itself. Certainly, at the outset of the period of expansion, there was great enthusiasm for the acquisition of new land in Italy, both to provide estates for the political class and plots for the cultivators, and the state found no shortage of takers to buy or rent what it acquired by conquest; the agricultural colonies it founded were quickly settled and generally flourished. Yet arguments that Rome’s wars were deliberately undertaken to amass slave populations as a labour force on the expanding estates of the political class appear farfetched, as do those that Roman governments thought in such primitive terms as loot; the Italy which succumbed to Roman conquest was a largely moneyless region, and had little to yield in precious metals or minerals or rich artefacts. Nevertheless, ‘it was scarcely possible for a Roman to disassociate the expectation of gain from the expectation of successful war and conquest’. The two went together in the Roman outlook, as is best expressed by the classical historian William Harris: ‘Economic gain was to the Romans … an integral part of successful warfare and of the expansion of power.’47

  What most distinguished the warfare of the Romans from that of their contemporaries and neighbours was not its motivation — in that respect it was the headstrong and individualistic Greeks who stood apart — but its ferocity.48 So ferocious were the Romans of the later first millennium BC that, in broad historical perspective, their behaviour bears comparison only with that of the Mongols or Timurids 1500 years later. Like the Mongols, they took resistance, particularly that of besieged cities, as a pretext justifying wholesale slaughter of the defeated. Polybius, the foremost Roman historian of the city’s early military history, describes how Scipio Africanus, after storming New Carthage (Spanish Cartagena) in 209 during the Second Punic War,

  directed [his soldiers], according to the Roman custom, against the people in the city, telling them to kill everyone they met and to spare no one, and not to start looting until they received their order. The purpose of this custom is to strike terror. Accordingly one can see in cities captured by the Romans not only human beings who have been slaughtered, but even dogs sliced in two and the limbs of other animals cut off. On this occasion the amount of such slaughter was very great.49

  The experience of New Carthage was widely repeated, sometimes in cities that had capitulated in the hope of averting a massacre, and even on the field of battle; Macedonians who fell in the campaign o
f 199 BC were later found by their companions as dismembered corpses, a sacrilege to all Greeks, who thought it a duty to bury the dead of battle, whether friend or enemy. The practice persisted into the first century AD, if the archaeological evidence for a massacre at Maiden Castle in Dorset, during the second Roman invasion of Britain, bears the interpretation usually put on it.

  Harris concludes:

  In many respects, [the Romans’] behaviour resembles that of many other non-primitive ancient peoples, yet few others are known to have displayed such an extreme degree of ferocity in war while reaching a high level of political culture. Roman imperialism was in large part the result of quite rational behaviour on the part of the Romans, but it also had dark and irrational roots. One of the most striking features of Roman warfare is its regularity — almost every year the Romans went out and did massive violence to someone — and this regularity gives the phenomenon a pathological character.50

  In the context of comparative military history, this should not surprise us. The impulse to violence takes many forms, we have seen, and if most people shrank from expressing it directly when to do so entailed risk to their own bodies, a minority did not. Phalanx warfare, though it limited its effects by its essentially ponderous nature, inflicted appalling violence at the moment of contact, and to engage in it demanded a violation of both the instinct of self-preservation and the widespread cultural inhibition against face-to-face killing. What the Greeks learned to overcome in one fashion, the Romans learned in another. For all their social and political sophistication, they seem to have preserved from somewhere in their primitive past sufficient of the psychology of the hunter to fall on fellow humans as if on animal prey, and do their victims to death with as little regard for life as is sometimes shown by one wild species for another.