One Greek constitutional state which continued to prosper and grow strong in a world of warlords was Rhodes. Like the political leagues of the Greek mainland, the Rhodian federal government enjoyed an advantage over more narrowly conceived city states. The Dorian Greek settlers of the island had originally founded three main cities: Ialysus, Lindus and Camirus. Despite its Dorian population, the island had, throughout most of the Peloponnesian War, been a member of the Athenian League. Only in 411 BC, when Athenian power was in decline and Lysander had, with Persian financial support, made Sparta a naval force in the eastern Mediterranean, did Rhodes renounce her Athenian allegiance. About this time, the cities of the island formed a federation, with a newly founded capital city and a central government. Each member city, however, preserved a large measure of local autonomy.
Rhodes had grown rich by carrying corn and other cargoes in its ships; Alexander’s destruction of Phoenician Tyre rid the island state of a dangerous trade competitor. At the same time, the Macedonian mastery of the entire Persian empire and the consequent abolition of political frontiers in the eastern Mediterranean threw open new coasts and harbours to Rhodian vessels. In the time of Alexander’s Successors, Rhodes managed to hold a balance of power and ingeniously preserved its independence. The Rhodians flattered and conciliated the contending dynasts around them, refusing to enter into any alliance with one against another. This in itself would not have been enough to secure the island’s liberty if Rhodes had not possessed a strong navy of its own. Such a navy, however, the Rhodians were wise and bold enough to maintain. In their moderate form of democracy, the rowing crews of the ships were recruited from the poorer classes, while the officers were drawn from wealthier families. They did not need to rely upon mercaneries.
Rhodes was, in fact, the successor of Athens as the leading Greek naval power. As at Athens, such power was dependent largely upon civic patriotism. But as a comparatively small island, Rhodes enjoyed some advantages which the Athenians had not possessed. The Rhodians could rely entirely upon their navy for defence. Immune to land invasion, they were not obliged to organize an army or build Long Walls to secure communications with their docks and shipyards. Indeed, the famous Rhodian slingers served for the most part as mercenaries in foreign armies and may best be considered as a source of “invisible earnings”. Moreover, the island’s rocky coast lent itself admirably to fortification against sea-borne attack, as the Crusaders of a later age were not slow to realize.
Rhodes’ naval supremacy in the eastern Mediterranean was also a bulwark against piracy. Unfortunately, any power strong enough to subdue pirates in the ancient world usually felt at liberty to behave with piratical lawlessness itself; such protection as it offered became a “protection racket”. Rhodes, however, was an exception in this respect and, deeply committed to constitutional principles, evolved a code of maritime law, which the Romans later imitated and embodied in their own laws. Indeed, modern law, based upon the Roman, may indirectly owe something to Rhodes.
The Rhodian foreign policy, bent on preserving a balance of power, could not at all times be sustained. Forced at last to take sides either with Ptolemy or Antigonus, the Rhodians considered that their best prospects lay in alliance with the former. Rhodes was accordingly blockaded and stormed by Antigonus’ celebrated son, Demetrius the Besieger (Poliorcetes). This ordeal, however, the island triumphantly survived, re-emerging with enhanced power and prestige.
Any further allusion to the siege of Rhodes is perhaps best prefaced by some general remarks on the evolution of Greek and Macedonian siegecraft in general. Even before the Peloponnesian War, Pericles had used battering rams against the island of Samos, when it revolted from the Athenian League in 441 BC, and we have already referred to the siege of Plataea (429–427 BC), in which the Spartans and their allies used rams in conjunction with an earthen ramp, flaming arrows, fire faggots and elaborate walls of circumvallation. In the fifth century BC, the advantage lay with the besieged and the prospect of taking a town by assault presented enormous difficulties. The Athenian Long Walls were never stormed and the Athenians themselves succeeded in taking Potidaea only after a long blockade. These circumstances are explained largely by the Greek weakness in archers and slingers and their general neglect of missile warfare. In default of covering fire, all siege operations were exposed to counter-attack from the besieged walls, as happened at Plataea, where the heads of the battering rams were broken off by heavy beams dropped from the fortified walls above.
With the introduction of missile warfare, the situation was crucially altered. The greater use of hand missiles was soon followed by the employment of artillery engines, depending for their projectile power on cables of twisted sinew. The introduction of the arrow-firing catapult was attributed to Dionysius I of Syracuse. This machine was a giant crossbow mounted on a heavy wooden frame, launching a correspondingly heavy-headed dart. Philip II of Macedon used such machines when he besieged Perinthus in 340 BC. But the first use of catapults to hurl rocks probably came rather later. Alexander certainly had such catapults at the siege of Tyre.
Artillery of this kind could, of course, be employed by the besieged as well as the besiegers. In fact, its use operated to the advantage of those within the walls, since their fortifications were of a more solid and permanent nature and could be built with narrow ports, embrasures and battlements, behind which the artillerymen could operate under cover. Besieging armies countered this advantage by constructing elaborate towers and penthouses, with ports for artillery which matched those of the defenders. Such structures also sheltered battering rams. The obvious way of operating a battering ram was to suspend it from an overhead beam and swing its head against the target. It could also be mounted on wheels and thrust violently against the wall under attack by a large and muscular crew. More sophisticated types were developed, in which the shaft of the ram slid in a wooden channel; it was then repeatedly winched back, as if in a catapult, and projected against the wall.
Penthouses, often on wheels, could also be used to screen the operations of minors and sappers or those who wished to fill in the fosse before an enemy rampart. Covered by artillery and missile support, assault with scaling ladders became increasingly effective. Ladders were not always of wood; a kind of leather-and-cord network ladder was also in use.
The defenders, for their part, sometimes hung on their battlements wooden placards which would be shifted in such a way as to dislodge any scaling ladders placed against them. These protective placards must, of course, in turn have been exposed to the assailants’ fire darts. As is the way of military technology, the series of devices and counter-devices was capable of endless prolongation, inevitably involving both attackers and defenders in enormous expense. A simpler and cheaper method of capturing a city was by means of treachery, and by treachery cities were often captured. This method, with all the precautions and counter-measures which we class under the heading of “security”, was allotted scientific consideration in the treatise of Aeneas Tacticus (late fourth century BC).
The Siege of Rhodes
Demetrius brought to the siege of Rhodes a vast armament of men and ships. Apart from his own fighting fleet of 200 vessels and his auxiliary fleet of more than 150, he had enlisted the aid of pirate squadrons. One thousand private trading craft also followed him, attracted by the wealth of Rhodes and the prospect of spoil. The whole operation was, in fact, a gigantic piratical enterprise. But Demetrius seems to have felt that it was “a glorious thing to be a pirate king”.
The main harbour at Rhodes, as well as the city, was fortified with towers and walls. Here the Rhodian fleet could safely rest; nor was Demetrius able to prevent ships with supplies from running his blockade. His first concern, therefore, was to capture the harbour. He at once proceeded to build his own harbour alongside, constructing a mole and protecting his seaborne siege operations from counter-attack by means of a floating spiked boom. At the same time, his army ravaged the island and built a huge camp on land adjacent to the city but out of missile range.
In the course of the siege, both sides employed the technical devices we have just described. Mining operations by the besiegers were met by the counter-mines of the besieged. At a fairly early stage. Demetrius’ men secured a footing on the mole of the main harbour, but the Rhodians prevented him from exploiting this bridgehead and he never captured the harbour. Later, as a result of a land attack, he actually penetrated the walls of the city, but the attack was contained by the Rhodians and those who had entered were mostly killed.
The most sensational feature of the siege was Demetrius’ mammoth tower, which was nicknamed the helepolis, “city-taker”, although in the event it failed to take the city. The helepolis tower was based on a huge square grille of timberwork, covering an area of 5,200 square feet (484 sq m). The tower was about 140 feet (90 cubits, 43m) high and the uppermost of its nine storeys was 900 square feet (84 sq m) in area. As a protection against fire, the tower was armoured with iron plates on its three exposed sides; it was mounted on gigantic castors, the wheels of which were themselves plated with iron. The artillery ports of the helepolis were made to open and close by mechanical means and were padded with leather and wool as a protection against the shock of missile attack. Communication with the upper storeys was by means of two staircases, for ascent and descent respectively.
The machine was moved, presumably in relays, by 3,400 specially selected strong men. Some pushed from inside the structure, others behind. Diodorus assures us that the whole monstrous contraption could be rolled in any direction very smoothly. The helepolis was in effect a mammoth tank, far larger than any that have ever been driven by petrol engines. Despite every precaution, however, the Rhodians managed to dislodge some of the tower’s iron plates; when there was a real danger of its being set on fire, Demetrius ordered it to be withdrawn from action.
The entire Greek and Macedonian world, constitutionalists and dynasts alike, sympathized with the Rhodians during the siege. The conflict was, after all, one between law and piracy. Influenced perhaps by the unpopularity of his operations and convinced at last that he could not win, Demetrius came to terms with the Rhodians and went away to look for a war somewhere else. The Rhodians, overjoyed, rewarded the sacrifice of citizens, slaves and resident aliens as they had promised.
Demetrius had left his engines strewn around the city and the scrap metal which they yielded provided material for the huge statue which the Rhodians erected at their harbour entrance: the Colossus of Rhodes, one of the Seven Wonders of the World. A prodigy itself, the Colossus was a fitting memorial to a prodigious siege.
Fortifications during the generations which followed Alexander the Great were required to meet the challenge of increasingly sophisticated siegecraft and of armies equipped with larger, more abundant and more powerful machinery. Great importance was attached to counter-attack and to the creation of vantage points from which the besieger could be threatened on his flank by missiles. With this in view, ramparts were sometimes built on a saw-tooth pattern. Either the wall itself followed a saw-tooth contour or a straight wall was given a saw-tooth facing on its outer surface. The advantage of this device was that one saw-tooth projection gave covering fire to the next. Fortifications at Samikon, in the western Peloponnese, exemplify the asymmetrical slanted pattern of saw-tooth fortification and may be contrasted with the equilateral zig-zag which was adopted, for instance at Miletus on the coast of Caria.
As a defence against the approach of siege-towers, deep moats were often dug in front of the walls of a fortified position. Such moats had been dug in front of the Athenian city walls after the battle of Chaeronea and they were improved during the course of the succeeding century. On archaelogical evidence, these moats appear to have reached a depth of 13 feet (4m) and a width of 33 feet (10m). In some instances, moats were filled with water; when they surrounded cities, further protection was often given by a wall or palisade on the inner edge.
The construction of towers on the ramparts had long been a feature of Greek cities. These frequently projected in the manner of bastions and permitted a flanking attack on the besiegers. At the same time, the missile men who garrisoned them had the advantage of superior height and were in a position to oppose any siege-towers. Such defensive towers tended to become increasingly numerous. They were also increasingly independent of the curtain walls which linked them. At Myndos, near Halicarnassus, Alexander’s besieging force managed to destroy one defence tower, but its collapse did not affect the solidity of the wall. Conversely, during the siege of Rhodes, Demetrius’ forces were able to destroy the curtain wall on each side of a tower without destroying the tower itself. Towers were square, polygonal, semicircular or horseshoe in plan. The number of artillery loopholes and embrasures introduced by the builders tended to increase. Curtains between towers must have been built higher to the extent that the towers themselves were. Archaeological evidence suggests that walls of about 29.5 feet (9m) in height were normal during the fourth century BC; if attacks by a helepolis were expected, they were probably built higher. The height of a city’s walls was sometimes increased by the defenders during the course of a siege. The summit of a wall normally provided a communicating alley between towers and also a fighting platform fronted by a crenellated parapet. Such parapets, like the towers, might support tiled roofs; in which case they featured windows.
Both at Tyre and Rhodes, the besieged walls were difficult to attack on account of the rocks which lay in front of them. Considerable use was made of sites fortified by nature, even where the most defensible points did not closely correspond with the area needing to be defended. For this reason, city walls frequently embraced an area considerably greater than the city itself. It followed that some of the most imposing fortifications were constructed in areas where nature gave little help, and much effort was needed to strengthen the position.
Mercenary Armies, Pay and Booty
The siege of Rhodes, if one disregards its political futility, offers an interesting case study, since it presents a mercenary army at war with a citizen garrison. A citizen army was at its best fighting in its own homeland, in defence of its own womenfolk, children and property. A mercenary army, on the other hand, had the greatest inducement when it was an invading army, free to plunder and live off enemy country. This situation is illustrated by a late-third-century Cretan inscription, which, in recording the terms of a treaty, specifies that a soldier’s daily ration shall be one choinix1 of corn, except when he is quartered in enemy territory from which corn can be obtained. In the fifth century BC, citizen armies and navies serving away from home, whether provided with their rations in kind or in cash, expected no more than a subsistence allowance. Persian subsidies raised the daily ration allowance for trireme rowers from a half to a whole drachma, but there was difficulty in obtaining what had been promised. The drachma may be taken as containing 66.5 grains (4.3g) of silver; readers who are accustomed to inflation accounting may calculate what this means in terms of today’s commodity values.
The main reward for mercenary service during the fourth and third centuries BC was booty, not pay. Ready cash was often inadequate to provide payment. Cleomenes III of Sparta was hurried into a disastrous engagement at Sellasia in 222 BC because he lacked cash for the retention of his mercenaries. It should be noticed that Cleomenes was conducting a defensive campaign on his own territory. In an offensive war such as he had waged earlier in Arcadia, booty had been available and mercenary remuneration could be based on results.
Prisoners might often change hands for cash ransoms. Before the siege of Rhodes, the Rhodians came to an agreement with Demetrius, according to which a freeman captured by either side should be exchanged for 1,000 drachmas and a slave for 500 drachmas. But most booty was in kind and captives were commonly sold as slaves. An invading army, as at Rhodes, was followed by a horde of expectant traders. Among these were large numbers of slave-dealers; after a victory, captives could be sold on the spot.
Apart from the inevitable fickleness of a mercenary army, its appetite for booty significantly conditioned the course of such wars as it was employed to fight. Even with citizen armies, it was hard for any commander to retain control over his men once they had fallen to plundering; for this reason a battle won in one sector of the field was often lost in another. It was an outstanding tribute to Alexander’s discipline at Gaugamela that he was able to withdraw his victorious Companions at the moment when the enemy was in flight and a rich spoil invited them, in order to help his hard-pressed left wing in that phase of the battle. Except for a small nucleus of Macedonians who perhaps felt themselves to be united with their leaders by a tie of common nationality, the armies of Alexander’s Successors depended mainly on mercenaries; this fact goes far to explaining why the wars which they fought were usually so inconclusive. A mercenary force possessed of the baggage train of a defeated army – let alone a town or territory which had sheltered the enemy – in its preoccupation with plunder would have little incentive to follow up a victory or pursue fugitives. Indeed, it was hardly in the mercenary’s interest to eliminate the opposing forces completely. By so doing, he would have deprived himself of employment and so a living.