Siege Weapons

Siege Weapons

Sieges were the neutron bombs of ancient warfare—a total concentration of military force on a fixed defensive, usually civilian, position. Whenever a city retreated behind its walls and a standoff loomed, the attacking army surrounded it and cut off its supplies. Capitulation often took months or even years, depending on how well provisioned the town was. The besieging army needed a method to hasten surrender, a way to bring the walls down and allow them to move in for the kill. The Assyrians, one of the oldest-known civilizations (2000-612 b.c.), are thought to have invented siege warfare. One of their most effective weapons was the battering ram, a tool that was used and improved by both the Greeks and the Romans. The first rams were rather crude, consisting of little more than a tree trunk about 15 feet (4.5 m) long hung by a rope from a turret (about 18 feet [5 m] high) on a wheeled base. The business end was sharpened like an axe, and the log was swung repeatedly, usually at the gates. The soldiers that worked these devices were obviously sitting ducks for anyone with a bow and arrow or a pot of boiling oil, so they were covered by archery fire from their own troops while they worked. A battering ram shown on a seventh-century b.c. clay tablet was roofed with hides to protect its operators. While those inside the walls were preoccupied with the ram pounding at the gates and the constant hail of arrows, attackers with spears climbed scaling ladders, hoping to find a few holes in the defense and bring the whole episode to a victorious conclusion.

The ancient Greeks added other weapons to their siege arsenal, most notably several types of catapult, which had originally been developed by the Phoenicians. The smallest version, the katapeltes, could throw arrows or spears or even a small boulder with some accuracy to a range of about 250 yards (229 m). The petrobolos was larger and could handle a bigger payload--stones up to 55 pounds (25 kg) or so. Both models used twisted sinew or lengths of human hair as a spring to propel the missile. Another device adopted from the Phoenicians was the siege tower, a tall wheeled structure with a roof and a drawbridge that could be brought close to the walls, eventually disgorging its occupants onto the ramparts. As destructive as these machines were, the sturdy walls of most cities generally withstood the assaults made on them. The town of Plataea resisted the Athenians' fiery missiles during the Peloponnesian War by erecting barriers made of hides around its walls. The inhabitants of Syracuse stopped Athenian battering rams by pouring a fiery combination of sulfur and pitch on their attackers. At this point in history, the combined weapons of starvation and treachery carried the day far more often than military technology.

The best example of this is the famous Trojan horse, which, according to the Iliad, the Greeks used to capture Troy. In 398 b.c., however, the city of Motya fell after a siege by Greek forces. Dionysius I of Syracuse (405-367 b.c.) used towers, rams, and catapults to bombard the town. Later, men with scaling ladders climbed the walls and overran the defense. Alexander the Great (356-323 b.c.), the most successful Greek commander in history, also used towers, rams, and catapults in his conquests.

Few towns stood a chance against a Roman siege. Their first step was to surround it with a bulwark constructed just out of the range of fire; if a long siege was expected, the soldiers built a double-walled, roofed structure. Whatever the fortification, the object was to prevent anyone from getting out or bringing food in. The Romans too relied heavily on the battering ram. Their version used a tree trunk tipped with an iron ram's head, swung by as many as fifteen hundred men. Those closest to the walls were covered by a roof called a testudo, or tortoise, which shielded them from the various deadly objects dropped on them by the besieged.

Like the Greeks, the Romans also used various forms of catapult. The two heaviest models were the ballista and the onager, which could hurl rocks as large as 60 pounds (27 kg) as far as 500 yards (457 m). This is rather impressive when you consider that naval cannon in use at the time of the American Revolution had only twice the range for a shot that was half the weight--and both were about equally accurate. The onager, which means wild ass, got its name because it kicked up its hind end when fired. It had a shorter range than the heavier ballista, and was used at closer targets. Catapults, the smallest of the Roman hurling engines, could pivot from side to side, and were poised so that their elevation could be adjusted as well. They usually fired short but substantial spears from their 4-foot (122 cm) arms, and had a range equal to the ballistas. Mining was another favored tactic, and tunnels were dug to try to get under city walls. The occupants of the castle often retaliated by digging a countermine, usually an inescapably deep hole the miners would fall into, or a mass of straw soaked in oil and set alight. If enough water was on hand, the tunnel could be flooded. The cover of darkness was a useful tool as well. Roman besiegers would often build an earthen ramp gradually closer to the city each night, the idea being to bring the siege towers in to do some damage and eventually breach the walls. But the townspeople could, if they had the chance, build their wall correspondingly higher at that point, nullifying any advantage the ramp provided.

When the Roman Empire finally fell in the fifth century, the West began to struggle with invasions from "barbarian" tribes like the Vikings and the Magyars. Around this threat the feudal military and social system developed, and the castle became the surest means of defense. The old Roman siege weapons were still used, but the lack of military technique that accompanied the loss of civilization rendered them far less effective, even if later technology did make them more powerful. Medieval siege weapons were familiar variations of their Roman counterparts, although they were given new names and sometimes new purposes. Battering rams were still used, but were largely useless against a 10-foot (3 m) thick castle wall; their chief advantage was against flimsier city gates. Siege towers were called beffrois or cats, although their use was stymied by the water-filled moat that surrounded most castles. Scaling ladders were known as escalades, but moats presented problems here too, and it was difficult to assault a fortified castle from below while armed defenders rained all manner of opposition on their attackers. For these reasons, medieval armies relied heavily on those old standbys, missile-throwing engines, or gyns. The springal was a piece of light artillery that usually threw flaming darts. (As castle design evolved, roofs were made of lead to protect against this kind of attack.) The ballista became a kind of giant crossbow, hurling massive spears. Catapults came in two categories, the mangonel , or nag, which threw stones and bucked like the Roman onager, but was really a much clumsier machine. The trebuchet was the largest of the gyns, using an entire tree trunk as its base. Its size was so formidable that it was usually built on site during the siege. The design was unchanged until well into the sixteenth century, although it was eventually equipped with metal bearings. In addition to boulders and javelins, besieging armies would use almost anything else they could find as ammunition. Dead animals were especially spectacular, and for real emphasis nothing beat a live prisoner if the attackers could capture one.

Mining was another possibility, and one that was arguably more successful. The tunnel was supported with timbers, then, when the appropriate spot had been reached, the beams were doused with fuel and set afire. As the wood burned away, the ground collapsed and the walls tumbled. Later armies would use this technique to plant land mines and other explosives underground. The invaders could also try to ignite wooden gates by soaking them with pitch, but slits in the wall above the gates were often built to quash any such attempts. As cannonballs and gunpowder replaced the ballista and battering ram, the castle's inviolability began to crumble, and sieges became decidedly more one-sided. The siege of Constantinople in 1453 was a turning point in military history, for it marked the end of the medieval era. The strength of the city's walls had been legendary, but the Turks' relentless bombardment destroyed them in six weeks.