Siegecraft originated in Ancient Greece. This type of siege originated from the moment in which the stage of the mere siege was surpassed by an exceptional development of military techniques, which were hardly taken any further during the Middle Ages, until the invention of firearms. The importance of siege techniques was due to the increase in the strategic role of the city to the detriment of the territory in the overall defense of the polis.
Origins
Apart from the Mycenae tablet, in which slingers, archers and stone throwers are seen fighting a battle under the walls of a city, Homer's description of the chariot assault launched by the Trojans against the fortified camp of the Achaeans, and the anecdote of the Trojan Horse, there is nothing, except the fortifications discovered by archaeologists, that informs us about the evolution of Greek poliorcetics before the end of the Archaic Period.
Since the Neolithic, defensive concerns have presided over the organization of the urban plan. More than through the construction of fortified enclosures of very limited size and extent, one can observe the adaptation of civil architecture itself for military purposes: the streets are narrow and winding, while the walls of the houses are sometimes reinforced to serve as defensive wall, especially on the edges of the agglomerations. This protection system, despite its rudimentary appearance, is of great efficiency and allows to make the best use of the natural features of the terrain, with the least effort. In the 4th century B.C. it was still recommended by Plato, in Laws, who was concerned not to separate topographically the device of collective defense from the ordinary framework of private life, in order to increase the combativeness of the citizens.
The structural autonomy and architectural power of walled enclosures tended, however, to be reinforced in the course of the 1st millennium B.C., given the progress of construction techniques, the enrichment of communities and the concentration of social resources in the hands of palace aristocracies (perhaps also influenced by the Hittites, who by that time had already forged a reputation as experts in fortification).
Between the middle of the 14th century B.C. and the end of the 13th century B.C. the Mycenaean acropolis, then royal residences, was surrounded by imposing defensive walls of Cyclopean blocks, more or less well hewn and laid without mortar. Their width varied between 4 and 17 m, and their height between 4 and 9 m. Their layout was generally determined by the orography, but sometimes it was also divided into short rectilinear sections separated by small slits, as in Gla, a place located on an island in the Copais lake of Boeotia. The openings were scarce: four gates at Gla, a gate and a postern at Mycenae, Tiryns and Athens, generally provided with an access ramp parallel to the defensive wall and also flanked by massive projections forming a forecourt, as at Tiryns, or by towers, as at Mycenae, Athens and Gla.
The gates were the only weak points of the fortified perimeter; hence the exceptional precautions taken to force the assailant to present himself before them in an unfavorable position, on his left side, which was not protected by the shield and exposed to the weapons of the defenders. It was rather by besieging them that one could hope to seize these fortresses, in which the population of the territory probably took refuge; for this reason, the builders often took the precaution of fitting out subway galleries leading to fountains located at the foot of the defensive walls.
It does not seem that before the 5th century B.C. there was any modification in the art of fortifications and siege procedures. What is important in urban enclosures, whose number increased considerably from the archaic period onwards, was their static value, the passive aspect of their power; formed by a structure of sun-dried bricks, generally founded on a base of dressed stones, with few openings and equipped with some square flanking towers (especially near the gates), they were clearly not designed to withstand a full-fledged assault.
Historians' accounts show that besieges were, until the Peloponnesian War, the most widespread and effective method of siege. Once a countervaluation wall of unfired bricks or dry-laid stones had been built, sometimes supplemented on the outside by a circumvallation wall, the besiegers had no choice but to stand guard, draw on their reserves and be patient. In this way they recognized their inability to force their way into the city; an inability that revealed, above all, their reluctance to take such a risk, since for them, the main issue in the conflict was control of the territory.
During the Peloponnesian War, the Athenians were the only ones who had the economic means and the political courage to sacrifice in cold blood the defense of the territory to the safeguarding of the city, as Pericles had advised them, since for them it was the only way to maintain their empire (their tribute provider), which was threatened by the terrestrial superiority of the Spartans. Nevertheless, their strategy, despite its ultimate failure, prefigured to some extent the new strategy adopted by most Greek cities from the 4th century B.C. onwards, however circumstantial and conjunctural it may have been.
Development and practice of the assault This new strategy did not attach absolute importance either to the territory (as in the traditional strategy) or to the city (as in the strategy of Pericles). It made a weighted and gradual use of both, with which it tried to diversify the possibilities of resistance around the urban core, which henceforth became the last redoubt of defense. Thus, the conquest of the city, usually the repository of promising booty so necessary for the end of the conflict, became the main objective of the aggressors.
This tendency was accentuated at the beginning of the Hellenistic period. The development of Greek poliorcetics dates from the moment when —while the civic body tended to become detached from the territory and identified with the city— the problem of defense was presented in purely technical terms.
However, this strategic evolution would not have upset the siege procedures to such an extent if the quality of the troops and the general organization of the army had not suffered with the crisis of the polis.
Without the development of light troops, the practice of the assault, which required physical and psychological dispositions completely different from those of the siege, would have had more problems to impose itself. It was not until the emergence of states of a tyrannical or monarchical nature, capable of a war effort hitherto unknown, that a siege fleet large enough to make a siege a profitable venture became available. It was no accident, nor the mere effect of a specific cause of a technical, social or political nature, that Greek poliorcetics reached its apogee in the time of Alexander the Great and the Diadochi, during the course of the fierce conflicts that accompanied the birth of the empires. It was the result of a conjunction of new forces and appetites, liberated by the explosion of the city: the disappearance of the citizen-soldier, the failure of the hoplitic mode of combat and the unleashing of power turned absolute, which fed itself and was concerned only with becoming greater.
Assault troops In the first place, the spread of the practice of assaults tended to increase the relative importance of light troops and probably also to lighten the equipment of the infantry. For Iphicrates, the ideal type of the "conqueror of cities" was the peltast.
On the other hand, it resulted in important tactical innovations aimed at improving the shock power of the assailants. Thus the Syracusans, at war with the Carthaginians, were the first Greeks to become aware, at the end of the 5th century B.C., of the effectiveness of the "continuous assault" carried out by successive waves and, consequently, of the need to have supplies. For the same reason, from Alexander onwards, commandos specialized in scaling defensive walls were formed within the armies.
Finally, siege warfare contributed to revaluing the use of surprise, trickery and treachery to the detriment of open confrontation, as well as individual valor, more or less provoked by the bait of rewards, to the detriment of collective heroism.
Thus, the improvement of poliorcetics in Greece favored the decline of the citizen-soldier and the development of military professionalism, while aggravating the social and political crisis that had been its origin; all the more so since it was accompanied, from the time of Dionysius I (early 4th century B.C.) to that of Demetrius Poliorcetes (early 3rd century B.C.), by a considerable development of military technology, which required a greater mobilization of material and human resources.
Incendiary weapons
A weapon as primitive as fire did not cease to play an important role in siege warfare throughout ancient times, because wood remained an essential material in civil architecture and even became an essential part of the composition of the most exposed points of the fortifications (gates, patrol paths and various palisades), and also because of the refinements that occurred in incendiary weapons to end the protection systems devised by the defenders.
Often it was limited to creating immense bonfires, carefully calculating the direction of the wind. The assailants threw pitch and sulfur on it to activate the combustion, while the besieged created in front of their buildings screens of fresh skin and threw against the bonfire water, earth and vinegar (whose qualities as an extinguisher were highly appreciated by the ancients). It was also known from very early on how to act from a distance and with greater precision. Arrows lined with flaming tow were used from the medical wars onwards. During the Peloponnesian war a kind of spear-torch of which Thucydides has left us a detailed description was developed and tested against the Athenian entrenchment of Delium in the winter of 424 B.C.
These procedures were perfected and diversified from the 4th century B.C. onwards, the besieged often having more and more and better means to destroy the works of carpentry that the assailants erected in front of their defensive walls. Numerous types of incendiary devices were then invented, similar in concept to those described by Aeneas Tacticus:
The recipes for incendiary products were gradually refined.Mercier, M.: Le feu grégois. Les feux de guerre depuis l’antiquité. La poudre à canon; Partington, J. R.: A history of Greek fire and gundpower (p. 141). Aeneas recommended the use of "a mixture of pitch, sulfur, tow, incense powder and pine sawdust". After Alexander's expeditions, liquid fires were sometimes used, such as asphalt or liquid bitumen. In the 3rd century, Sextus Julius Africanus even advocated the use of an "autonomous" fire, which was an advertisement of the Greek fire invented by Callinicus of Heliopolis around 668-673:
However, Archimedes would do even better if it is true, as late authors say, that in 211 B.C. he managed to set fire to the Roman ships participating in the Siege of Syracuse using mirrors to capture the fire from the sky.
Framed works
Battering ram Another type of siege machines was formed by the "framed works". These included, in the first place, the battering rams, which would have been "invented" during the Siege of Samos,The Siege of Samos lasted almost 9 months, from August 440 BC to May 439 BC. in 440-439 B.C., by an engineer of Pericles, Artemon of Clazomenae. He was undoubtedly inspired by Eastern models, since this type of machine was in common use in Western Asia from the time of the last Assyrian Empire, and was known even much earlier, in more primitive forms, from the 3rd millennium B.C.