The Persian and Peloponnesian wars were a period of sustained conflict, quite unlike anything that the Greek cities had previously experienced, bringing about radical changes in government and warfare. These were really wars of survival, and the power of central governments had to be strengthened if fleets were to be built, fortifications constructed and maintained and armies raised. In purely military terms, the most obvious and distinctive element in the Greek land forces was the phalanx. By the late fifth century the hoplite phalanx had become not merely the core but the dominating force in Greek armies. The individual soldiers wore helmets of leather or bronze and protected their bodies with leather straps or jackets studded with metal plates, together with the great shield. The phalanx was evolving into a very tight close-order formation, unlike the rather looser units which had, for example, fought at Marathon. The problem was that moving and maintaining formation required discipline, a quality notably lacking in Greek citizen armies, with the exception of that of Sparta whose population was dwindling. By the end of the fifth century the phalanx had undergone a decisive change. It was now commonly made up of professional soldiers. The endless wars undermined Greek agriculture, so that men who had once been farmers were now ready to be paid soldiers.
Moreover, armies and tactics became more varied during the long wars. Cavalry and light-armed troops, like the Thracian peltasts and Cretan archers, began to be marshalled as separate forces on the wings of the hoplite centre, and their mobility made them very useful. On broken ground the phalanx could not maintain its solidity and thus became very vulnerable. In 426 Demosthenes led an Athenian army against the Aetolians who had only lightly armed troops. He relied on his own archers to repel their attacks:
But as long as the Athenian archers had arrows and were able to use them, they held out since the Aetolians were light-armed and retreated when they were shot at. But after the commander of the archers was killed, his men dispersed, and the hoplites were worn out through being subjected for a long time to the same fatiguing actions: the Aetolians pressed them and continued to shower them with javelins. The Athenians were thus routed and fled.
The following year, when the Spartan hoplites attacked his army, Demosthenes sent forward large numbers of light troops armed with javelins, bows and slings, and they harassed the enemy so severely that they could not come to close quarters with the Athenians and so,
When many of them had now been wounded because they (the Spartans) were continually forced to remain in the same spot, they closed ranks and retreated to their last strong point on the island.
The hoplite phalanx was excellent at close quarters, but once commanders had learned to use light infantry effectively, it had to be used in conjunction with them. This placed a premium on coordination, training and discipline which imposed impossible demands upon citizen-soldiers, reinforcing the trend towards mercenary armies. City-states like Athens and Sparta had evolved the phalanx of spearmen with shields out of necessity, and in the Persian wars it showed great potential against cavalry. But by the end of the fifth century it was clear that only professionals could be trained and disciplined as an element in more complex armies, ushering in a period of tactical experiment. The Athenian general Iphicrates devised a kind of hybrid – lightly armed peltasts equipped with very long spears who were crammed very tightly into the phalanx – but this was not sustained. The Thebans at Mantineia in 418 and Leuctra in 371 attempted with some success to overcome the tendency of the phalanx to drift to the right in the attack, as each man sought the protection of the shield of the man on that side, by sending a strong force forward on the left while a weak right was held back. The growing size and diversity of armies placed an enormous burden on the Greek city-states, especially as siege warfare was becoming commoner.
The Greeks were for a long time very bad at sieges and for very good reasons. Citizen-soldiers recoiled from the price in blood involved in storming even modest walls. The alternative, a long siege demanding specialised machinery, was cripplingly expensive. In May of 429 BC the Spartans and their Theban allies besieged the small city of Plataea which had barely 500 defenders. The Spartans showed remarkable ingenuity in that they built a ramp of earth against the city walls and deployed battering rams – the first use of such methods by any Greek city. But they had no archers to cover their attackers and all assaults failed. In the end the Spartans built a wall and ditches around the city – a line of circumvallation – but the siege dragged on until the city’s food ran out in the summer of 428 BC.
In the fifth century the Athenians gained a formidable reputation as besiegers, largely because their fleet could move and supply large forces supported by ample numbers of slaves who rapidly dug lines of circumvallation around hostile or rebellious cities. This took time and money; the siege of Potidaea, begun in 432, lasted two years. Athens deployed 3,000 hoplites who were paid 2 drachmas per day plus 1 drachma for a servant. The siege cost 6,000 drachmas (or 1 talent) per day, and, therefore, 2,000 talents in all. The annual revenue of Athens at this time was probably 600 talents, so the siege bit deep into Athenian reserves. Usually, however, the very act of setting the siege and the elaborate preparations for attack strengthened the peace party within a besieged city and a surrender was obtained, either by betrayal or negotiation.
The Athenian siege of Syracuse in Sicily, 414/13 BC, exposed the limitations of this method. Athens had dispatched a huge fleet and army, and although some battering rams were deployed, their generals seem to have been counting on dissent within Syracuse, but the war party in the city conducted a very active defence and checked all efforts to surrender. A Spartan relief force appeared, the Athenians were trapped and they suffered a terrible defeat which, in effect, broke the Athenian Empire.
When, in the fourth century, the Phoenician city of Carthage attacked the Greek cities of Sicily, their methods were quite different. Siege-towers and cats were built to provide covering fire for attacks on the wall, and battering rams were deployed. Above all, they were ready to storm cities, accepting high casualties amongst their soldiers, many of whom were mercenaries. Moreover, terror was exploited as a weapon: cities which failed to surrender were destroyed and their populations butchered as lessons for others. These were the methods of Assyria, Babylon and Persia. The Sicilian Greeks had no choice but to emulate both their elaborate equipment and their brutality.
Greek ingenuity, in fact, added to the horrors of war by inventing the first mechanical bow: the gastraphetes, ‘belly-bow’. This was originally a composite bow mounted horizontally on a wooden stock within which a slider was drawn back against the bowstring by a ratchet operated by handles. The front of the stock was placed against a wall and the whole was braced by the holder’s belly. Once the slider was fully drawn back it was anchored by a trigger whose firing released the arrow. The arrow was much heavier than an ordinary arrow and, because it had a flat trajectory, rather more accurate. This weapon was enlarged and developed to throw heavier darts and rocks, or reduced in size to the classic crossbow. By 340 BC the Greek world had developed torsion-powered catapults. In the two-armed version the large horizontal bow was replaced by two arms each mounted in a coil of sinew, and the string and missile were drawn back by a ratchet. The onager (mule) had a single upright arm whose bottom was buried in a horizontally mounted coil of sinew. The arm was drawn back against the torsion of the coil and suddenly released to kick against a strong horizontal bar, projecting a small stone. All these were essentially anti-personnel weapons, though they could be scaled up to throw stones capable of damaging fortifications.
The military achievements of the Greeks were remarkable, particularly their defiance of the Persian Empire in the fifth century. The phalanx, as the Stele of the Vultures indicates, was an ancient military formation for fighting the close-quarter battle, though of course how tightly it was formed varied from time to time and occasion to occasion. The genius of the Greeks was to realise that the phalanx, which they had adopted out of the same necessity as so many cultures, could be made into a very effective counter to the Persian cavalry, and the sheer desperation of their fight against Persia inspired their soldiers to accept the discipline which would make this effective. At Plataea the defeat of the Persian cavalry exposed the lightly armed Persian infantry to defeat at the hands of the hoplites. Commanders recognised the value of the phalanx, but the spirit of the citizen-soldiers, so vital against Persia, was not something that could always be sustained. In the course of the subsequent intra-Greek wars the vital development was the professionalisation of the phalangists, because the steadier and more disciplined the soldiers of the phalanx, the stronger the formation and the greater the chances of success.
Nothing illustrates better the quality of these professionals than the story of Xenophon and his 10,000. These were Greek mercenaries hired by Cyrus of Persia in his bid for the throne. Xenophon, who later commanded them, makes it clear that Cyrus was seen as providing an economic opportunity for these shrewd Greek entrepreneurs:
The majority of the soldiers had not sailed from Greece to undertake this mercenary service on account of their neediness, but because of the reports of Cyrus’ character that they had heard; some brought others with them, while others had spent money of their own on this undertaking and others had abandoned fathers, mothers or children with the intention of earning money for them and returning once more since they had heard that those who served with Cyrus had enjoyed many benefits.16
In 401 BC they were victorious at Cunaxa, but Cyrus was killed. This led to negotiations with the victorious party at the Persian court during which their leaders were betrayed and killed by the Persians. The Greek soldiers then formed themselves into a kind of mercenary republic, electing Xenophon as their general, and fought their way up the Euphrates and back to Greece across northern Anatolia.
The Persian wars and then the long quarrels of the Greek city-states created a kind of military laboratory in Greece, stimulating ideas and new developments. The most obvious effect of this was the development of the hoplite phalanx. It became the very embodiment of close-order, a tight mass of men working together, able to resist enemies with their hedgehog of spears and to threaten them by sheer weight and momentum. However, this was only really achieved as the citizen-soldier was superseded by the professional soldier. But the hoplite had never been the only soldier on the battlefield, and commanders began to think seriously about how to combine archers, slingers and javelin throwers to the best effect, creating armies which were much more diverse and more capable of manoeuvre and attack in a wide range of circumstances. This was accompanied by an assimilation of the siege techniques of other peoples, and the invention of new devices like the catapult. What the Greeks did not do was to develop cavalry. That the environment in which they fought – in Greece proper and in Magna Graecia – was not particularly suitable for mounted warfare was a strong reason for this. But, in addition, they may have disdained cavalry because of its limitations: horsemen were missile throwers whose attacks could be held at bay by discipline and close-order, the qualities at the heart of agro-urban warfare as exemplified by the hoplite phalanx.
By contrast, the Persians, who had to fight over vast areas and open plains, continued to focus on cavalry. It is often wondered why the Persians did not train heavy infantry to replace their lightly armed foot. The reasons for this are both general and specific. The Persians had some heavy infantry, the Karkades, but they too lacked the means to achieve systematic training and relied on native skills which arose from civilian lifestyles. More specifically, the Greek front was not all that vital to the Persian Empire, and it managed to regain Anatolia by an adroit diplomacy which exploited the quarrels of the Greeks. The priority for the Persian Empire was speed of movement and the ability to fight in other places, especially on the long Asian frontiers where cavalry was the most useful arm. No power can be strong everywhere and in every aspect of war, and the Persian army was no exception to this general rule. And when they wanted heavy infantry, they could always hire them at need from the quarrelsome city-states of Greece whose mercenaries were perfectly willing to serve for money.
In the fifth and fourth centuries BC external attack and internal strife made Greece a forcing house of war. None of the Greek city-states could afford to master all these new techniques, especially as many of them had simultaneously to support fleets. As a result no empire of Greece arose, because neither Athens nor Sparta nor Thebes had the means to consolidate their momentary supremacies. But the military methods which the ingenuity of the Greek city-states had developed could be adopted by others. Moreover, the Greeks lacked cavalry. Thus the classic elements of agro-urban armies down to the nineteenth century – heavy infantry supported by light missile-men – had not yet combined with cavalry. But the horse had enormous potential which was realised under a commander of genius, Alexander the Great.