Hellenistic Military Developments IV

Military Technology

In terms of military technology, the fourth century must be viewed as revolutionary, and the many clever and deadly machines so closely identified with the Philip II, Alexander the Great, and Demetrios Poliorketes set the standard for the rest of the Hellenistic period. But they were not the first to recognize the practical value of siege machines and artillery. To Dionysios I of Syracuse goes the credit for the invention of the catapult (katapeltikon) in 399 (Diod. 14.42.1). Some have questioned this testimony, whereas others have accepted it at face value. What is certain is that Dionysios built mighty machines of war to expel the Carthaginians from western Sicily. He was fully aware of the Carthage’s deadly use of siege towers and battering rams against the Greek cities of Selinous, Akragas, and Gela in the years from 409 to 406.

Dionysios was a quick student and only needed the right opportunity to try out his new bolt-shooting catapult and his own siege machines. In 397, he attacked the island fortress of Motya, the Carthaginian base of operations in western Sicily (Diod. 14.47.4-53.5). Dionysios’ “engineers” (architektones) began the construction of a mole to the island, as Alexander the Great would do at the siege of Tyre in 332. When a Carthaginian relief fleet arrived, they were forced to withdraw under the missile onslaught of Dionysios’ archers and slingers stationed on the ships and his land-based catapults. Diodorus comments that this weapon caused “great distress” (megalen kataplexin) because it was a new invention (to protos eurethenai, 14.50.4). Finally, his mole finished, Dionysios brought up war machines of every type, battering rams, and siege towers, six stories high, equipped with gangways to drop down on the houses. His arrow-throwing catapults – which did not seem to have been placed inside the siege towers as they would later be by Demetrios Poliorketes – kept the defenders off the walls (Diod. 14.51.1-7). Finally, the fortifications were breached, and the city fell. In the siege of the Greek city of Rhegion in 388, Dionysios constructed a great quantity of siege machines (mechanemata) and of such unbelievable size that they shook the walls (Diod. 14.108.3).

Having introduced the catapult and siege warfare on a massive scale, Dionysios’ military thinking was apparently not readily adopted by the city-states of mainland Greece. Aineias Taktikos, writing in the 350s, confirms the use of large siege machines (megala mechanemata), now equipped with catapults (katapaltai, 32.8), but fails to suggest that the besieged city defend itself with its own artillery. Perhaps he assumed it. In any case, a technological breakthrough will occur at about this time – the introduction of the torsion catapult, perhaps by Philip II of Macedonia. The old catapult (gastraphetes) drew its power from a composite bow, whereas the new catapult used vertical torsion springs of corded human hair or sinew. When the bow was drawn back, the springs were twisted tighter and tighter. After the arrow was released, the springs returned to their former static position. The torsion catapult generated significantly greater striking force.

Philip II of Macedonia is generally credited with having introduced the torsion catapult in the 340s, and even if this cannot be decisively proved, there is no question that he was committed to advanced military engineering, and this fascination was passed along to his son, Alexander, and to the Successors, notably, Demetrios Poliorketes, Pyrrhos, and Agathokles of Syracuse. Military engineers now begin to be identified as individuals, Polyidos the Thessalian and his students Diades, who invented mobile siege towers (Vitruvius 10.13.3), Charias, Poseidonios, Epimachos of Athens, and Hegetor of Byzantion. The sieges of Perinthos and Byzantion in 341/085 were a portent of things to come: Philip constructed 120 ft siege towers, taller than the city towers, rocked the walls with battering rams, and mined long stretches of the walls. He deployed a wide assortment of catapults (oxybeleis) and rained arrows down on the defenders on the battlements. Fortunately for the Perinthians, they were able to receive reinforcements of men, arrows, catapults (katapeltas) from Byzantion to counter Philip’s siege weapons. Diodorus (16.74.5) tells us, however, that Philip had prepared a plentitude of arrows, siege machines (mechanon poliorketikon plethos), and other devices to carry on the siege. Perinthos could not be taken, however, and Philip initiated a second siege at Byzantion to cut off the supply route. In the end, the arrival of a coalition fleet led by Athens forced Philip to break off both sieges.

Heavy artillery catapault of the type probably mounted by Demetrius on his mighty siege engines used in his attack on Rhodes, which is thought to have been launched from Loryma Sound.

This military setback did not discourage Philip from developing his siege machinery, and the most obvious success story was his son’s siege of Halikarnassos in 334 and of the Phoenician island fortress of Tyre in 332. His mole, reminiscent of Dionysios’ at Motya in 397, allowed him to deploy siege machinery by land, whereas his catapult-mounted ships attacked the walls of Tyre by sea. Here, as at Halikarnassos, a new type of catapult was deployed, a stone thrower (petrobolos). This allowed the besieger to breach the walls themselves or destroy buildings within the walls, not just chase off the defenders from the battlements. A catapult was constructed to accommodate a specific weight of stone ball, and preserved examples range from 4.4 kg to 65.5 kg. Examples of catapult balls have been found at Rhodes, Pergamon, Tel Dor, and Carthage. The mother of all petroi weighed 78 kg (or over 170 lbs)! This megalithic monster belonged to Demetrios Poliorketes.

Aristotle, the teacher of Alexander and friend of the Macedonian court, recognized that a new age of warfare had arrived in the late fourth century. In his Politics, he comments that it is essential to possess the strongest fortifications to survive the new inventions in missiles (i. e., catapult bolts) and siege machines (tas mechanas . . . pros tas poliorkias, 7.10.6; 8). He cautions that, as attackers develop new machines of war, so must the city defenders. The Greek word repeatedly used in the text is a derivative of the verb eurisko, “to discover,” or “to invent.” It was the ancient equivalent of the arms race. Certainly, he has Philip and Alexander in mind with these remarks. In his narrative of the great siege of Rhodes, Diodorus would say the same things about Demetrios Poliorketes: “Demetrios deeply worried the Rhodians; not only by the size of his siege engines and the magnitude of his army, but also by the king’s energy and ingenuity in sieges. For, being “mechanically inclined” [eumechanos] and devising many things beyond the art of master builders, he was called “Poliorketes”; for he displayed such superiority and force in his attacks that it seemed that no wall could withstand them” (20.92.1-2). Diodorus continues: “For it was in his time that greatest weapons [bele] were perfected and engines [mechanai] of all kinds far surpassing those that had existed among others; and this man launched the greatest ships after this siege, and after the death of his father” (20.92.5, Loeb trans.).

The military exploits of Demetrios for the years 307-303 amply justify this praise. During the campaign to liberate Athens from the control of Kassandros’ agents in 307, Demetrios besieged his garrison on Munychia in the Peiraieus harbor. For two days, his catapults hurled arrows and stones at the troops defending the battlements and finally cleared the wall for a full-scale assault. Munychia quickly surrendered (Diod. 20.45.5-7).

We have already discussed Demetrios’ great victory over Ptolemy’s fleet off Salamis in Cyprus in 306 and his use of ship-borne catapults, but he also besieged the city by land with artillery, notably arrow-shooting and stone-throwing catapults of all types (katapeltas oxybeleis kai lithobolous pantoious) [Diod. 20.48.1]. The most famous siege machine was the helepolis, literally, “city-taker.” It stood 135 ft high and was mounted on four large wheels. In each of its nine stories, Demetrios placed artillery: the largest stone-throwing catapults on the lower levels (capable of hurling a stone of over 170 lbs); in the middle levels, the largest arrow-shooting catapults; and in the upper stories, the lightest of the stone-throwing and arrow-shooting catapults. It required 200 men to operate these artillery pieces within the tower. He cleared the parapet walls with a barrage of stones and arrows. The defenders of Salamis gained a temporary reprieve by burning down the siege engines with fire arrows shot from the walls. Demetrios’ naval victory, however, sealed its fate, and the city surrendered.

In 305, Demetrios began the great twelve-month siege of Rhodes. In addition to a huge army, he had at his disposal a huge supply of armaments for the siege. He equipped the prows of his ships with arrow-shooting catapults (oxybeleis) [20.83.1], as he had done at Salamis the year before. He also refitted (armored?) the lightest of his ships with planks and port shutters, and put long-range arrow-shooting catapults on deck, along with some Cretan archers. Directing his attack at the harbor, Demetrios fastened together two cargo ships and built two tortoise-shaped sheds (chelonas) on their decks to house and protect his arrow-shooting and stone-throwing catapults. The Rhodians responded with artillery of their own and equipped cargo ships with a large number of arrow-shooting and stone-throwing catapults of all sizes (20.85.4). The contest for control of the harbor went on for eight days, Demetrios destroying the Rhodian artillery on the mole with his heavy stone-throwing catapults (Diod. 20.87.1), but finally he was forced to withdraw. After a week, Demetrios furiously attacked the Rhodian harbor fortifications again, this time with a combination of fire-arrows, stone-throwers, and arrow-shooters (20.88.1-3). The Rhodians counter-attacked with three of their best ships, ramming two catapult ships of Demetrios. The Rhodians were eventually able to retake the mole and open the harbor. Reinforcements and supplies then arrived from Ptolemy I and Knossos.

The Helepolis at Rhodes

Demetrios shifted his siege operations to the land walls. He constructed another mobile helepolis, “a city-taker” siege tower, even grander than the one he had deployed at Salamis (Diod. 20.91.2-8). This monster was 120 ft high, weighed 360,000 lb, and was invented by the Athenian Epimachos (see also Chapter 12 in this volume). It was fitted with iron plates on three sides to counter the Rhodian catapults and was punctuated with shuttered apertures for the artillery pieces. Mounted on eight huge solid wheels, it required 3,400 men to move it. It was the terrifying size of these siege engines that prompted Diodorus’ attribution of “Poliorketes” to Demetrios (see previous discussion).

At this point in Diodorus’ narrative, we learn that the Rhodians dispatched naval squadrons to attack Demetrios’ ships and cut off his supply lines. One of these squadrons seized a convoy of cargo ships bringing materiel for Demetrios’ siege machines and captured eleven “renowned engineers” (technitai ton axiologon) who were specialists in missiles and catapults (katapeltas, Diod. 20.93.5). This, too, is a sign of the times – military science and its practitioners were invaluable to warfare. It is no accident that our fullest sources for military technology come from Hellenistic writers like Ktesibios of Alexandria (mid-third century), Biton (third century), Philon of Byzantion (ca. 200), the Roman Vitruvius (late first century), and in the Roman period, Heron of Alexandria (ca. 62 a. d.). This continues a tradition of military manuals appearing in the fourth century (see previous discussion).

As for the helepolis at Rhodes, Demetrios filled his nine-story siege tower with heavy and light stone-throwing and arrow-shooting catapults (Diod. 20.95.2), as he had equipped his helepolis at Salamis (20.48.3, see previous discussion). With this siege machine, Demetrios was able to destroy the strongest of the towers (constructed of ashlar blocks) and shatter the curtain wall, effectively cutting off movement along the parapet. Heartened by the arrival of relief ships from Ptolemy, the Rhodians positioned all of their arrow-shooting and stone-throwing catapults on the wall to direct their artillery fire and fire arrows at the helepolis (20.96.3). Some of the iron plates broke loose, exposing the siege tower to fire, and Demetrios was forced to withdraw his machine to a safe distance. Diodorus records (20.97.1-2) that when Demetrios ordered his men to gather up the spent missiles on the battlefield, they recovered eight hundred fire arrows (pyrophoroi) of various sizes, and not less than 1,500 catapult arrows! We learn from Vitruvius that Diognetos, the military engineer of Rhodes, devised a plan to neutralize the helepolis: they flooded the approach to the walls during the night, and the tower became stuck in the mud the next day (10.16.7). The goal of a besieged city was always to keep the siege machines as far away from the city walls as possible; this could also be achieved by dry moats (or a series of them as at Epipolai on the heights above Syracuse), fire arrows, or counter artillery fire from the walls and towers. Eventually, Demetrios was forced to come to terms with the Rhodians.

One might expect that Demetrios’ reputation suffered from his failure to take Rhodes, but his epithet, “Besieger,” was secure. For example, in 303, one year later, Demetrios attacked Ptolemy’s garrison at Sikyon, and the garrison withdrew to the acropolis. When Demetrios paused in bringing up his siege machines, the garrison “in panic” (kataplagentes) at the prospect of the coming assault, surrendered and sailed back to Egypt (Diod. 20.102.2). In the same year, Demetrios moved his war machines against the garrison on the heights of Acrocorinth. He intimidated them into surrendering by his deadly siege weapons and his reputation as a master of siege warfare (eumechanos) (Diod. 20.103.2). The Macedonian tradition of siege warfare continued on in the family of the Antigonids: In 217 Philip V campaigned against the city of Phthiotic Thebes in the region of Thessaly. In his train, Philip V assembled 150 arrow-shooting catapults and 25 stone-throwers (Polyb. 5.99.7).

After the siege of Rhodes, probably the most famous one was that of Syracuse in 213-211 by the Roman general Marcellus. The long-reigning ruler, Hieron II, had devoted much attention to the fortifications of the city. His chief military engineer was the famous Archimedes, a native son of Syracuse. Much of the sophisticated fortifications at Euryalos on the Epipolai plateau may have been his handiwork, although earlier phases under Agathokles and even Dionysios I are probably preserved. It is generally accepted that as artillery became more and more powerful in the mid-fourth and third centuries, the defensive fortifications of Greek cities had to respond with equal sophistication and innovation. These changes included larger and more massive towers, the replacing of great circuit walls with outworks and tall towers with artillery batteries, the indented trace, higher and thicker double-faced walls with solid rubble fill to resist heavy artillery and to support defensive catapults, and replacement of vulnerable crenellated parapets by a solid screen wall or covered parados. The massive five-pillar artillery bastion at Euryalos is one of the best-preserved examples, and some of the most elaborate (and appealing) city walls come from the late Classical and Hellenistic periods. F. E. Winter aptly observed, “It is easy to understand why the Hellenistic period as a whole affords no real parallels to the sensational achievements of Philip II and Alexander the Great. Long-developed techniques of attack and defense had simply played each other to a standstill.”

In the siege of Syracuse, we learn of a number of siege innovations on both sides, for example, a full description of the sambuca deployed by the Romans to attack the sea walls (Polyb. 8.4.2-11). For the Syracusans, Archimedes directed the defenses with a series of clever devices: various-sized stone-throwers and arrow-shooters, heavier for long range, then lighter for closer action. He pierced the walls with loopholes and stationed archers and “scorpions” (skorpidia), small catapults, to shoot through them. Archimedes countered the sambucae with special cranes that swung over the walls and dropped heavy stones on top of them. Other pulley and crane devices lifted up the prows of the Roman ships with an iron claw and capsized them into the water (Polyb. 8.5-6.1-7). By land, Syracuse’s arrow-shooting and stone-throwing catapults inflicted great damage on the Romans, the effect of Hieron II’s money and Archimedes’ genius. The Romans now desisted from direct assault and invested Syracuse for eight months. The city fell only when an unguarded wall was scaled at night (Polyb. 8.37.2-11). Marcellus included catapults, ballistas, and other engines of war in his triumph (Livy 26.21.7).

For other Greek cities, we have epigraphical evidence of catapult use and training. Athens appears to have had catapults as early as the mid-fourth century. During the Lykurgan period in Athens (335-322), Aristotle (AthPol. 42.3) reports that the two-year ephebic program included training in hoplite combat, archery, the javelin, and the catapult (katapalten). Although the ephebic program was reduced to one year at the end of the fourth century b. c., these young men still continued to practice in the use of the catapult down to the end of the second century. Inscriptions from 321/0, 318/7, and 306/5 record catapults or parts of them in the storerooms. Still other inscriptions, spanning 200 years of the Hellenistic period, honor the artillery trainer, the katapaltaphetes, and at least in one case, we can trace the careers of several generations of Athenian artillery instructors from the same family, for example, Pedieus of Oia. From the nearby island of Keos (Kea), an early third-century inscription instructs the gymnasiarch to lead his ephebes out for practice in the javelin, archery, and the catapult three times a month, reminiscent of the training in Athenian ephebeia. A catapult and 300 arrows for the practice sessions are to be supplied by the Council and a competition with prizes organized. Finally, there are inscriptions from the gymnasion at Samos that record victor lists in arrow-shooting and stone-throwing catapults in the late third and second centuries.

Continued support for ephebic training by Hellenistic cities tells us that citizen militias still functioned in a world of professional soldiers, mercenaries, and the great and diverse standing armies of the competing kings. Recent scholarship has argued that the city-state and its institutions did not “decline” or disappear during the Hellenistic period; the polis lived on, still cherishing its autonomy and independence. In this world of near-constant war, the independent Greek cities and the leagues maintained their military readiness, either for local and regional struggles or to leverage concessions from the kings. The ephebeia and the Hellenistic gymnasion continued to convert young men into soldiers. The quasi-military festivals, like the Theseia or Panathenaia in second-century Athens, showcased and encouraged the military ethos of their citizens. And they hired mercenaries to man their garrisons and to augment their citizen forces, just as they had done in the past. In the end, the military developments of the Hellenistic period were extensions and expansions of the great age of military innovation in the fourth century. Gigantism and specialization were but stages in a process that defies sharp historical periodization.


In the end, it didn’t make much difference what incredible war machines or specialized and diverse arms the Hellenistic kings deployed on the battlefield; the wars were still won by the Romans. By the middle of the second century, they had eliminated the Antigonid kingdom and emasculated the Seleukid kingdom. Ptolemaic Egypt was not absorbed into the Roman Empire until 30, but Egypt was a de facto dependency of Rome as early as 169. The question has always been, why didn’t the Hellenistic kings do better against the Romans? Fortunately, we possess an acute analysis from Polybios who knew both systems firsthand. After the battle of Kynokephalai in 197, the preeminent Hellenistic Greek historian pauses in his narrative to compare the Roman legion to the Macedonian phalanx (18.28-32). His explanation has become commonplace: on clear and level ground, with no physical obstructions to break up the tight formation, the phalanx should be irresistible. But on uneven and obstructed terrain, the Roman legion was more flexible, could operate efficiently in smaller divisions (maniples), and its soldiers were more adaptable to the varying conditions. There are of course other factors, but one can only wonder how Alexander the Great might have fared at the battle of Magnesia or Pydna. It has recently been argued that the Hellenistic kings did try to respond to changing military realities by reforming their infantry more along Roman lines in the 160s, but it was obviously too little, too late. The Hellenistic world now belonged to Rome.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.