Siege technology was an aspect of medieval warfare that ranged in scope from very small-scale operations, as when some Byzantine local forces drove off nomad raiders by erecting a barricade of carts around their church, to massive endeavours involving thousands of troops and huge expenditure. It was a field in which Byzantine and Muslim superiority over Western Europe was initially pronounced. Despite their tendency to rely on established tactics and weaponry, the Byzantines possessed very advanced siege machines. For example the earliest illustrations of a great crossbow mounted on a chassis comes from an eleventh- century Byzantine source, and the late thirteenth-century Western scholar Egidio Colonna attributed thebiffa (form of trebuchet) with an adjustable counterweight to the Romans, by which he probably meant the Byzantines.
Siege works and engines from the time of the Crusades. (Bettmann/Corbis)
The crusaders arrived in the Near East with less sophisticated traditions. In attack they might dig trenches to isolate the besieged from relief, form a testudo (a close group of men with their shields interlocked over their heads) to enable men to force a breach, and even pose as a band of lost travelers in an attempt to trick the night watchman at Shaizar (mod. Shayzar, Syria) to open his gate. While besieging Damascus in 1148, a crusader army found itself counterbesieged in its own camp by defending forces, but two generations later, a crusader cavalry charge broke a Muslim garrison unit that emerged from the besieged city of Acre (mod. ‘Akko, Israel) to challenge them during the Third Crusade (1189-1192).
In defense, castles in Outremer had a minimal impact on full-scale invasions, though it took the Muslims a long time to reduce those that could not be taken by surprise. According to the Rule of the Hospitallers, the gates of castles near the frontier were closed after compline, the last service of the day, and were not to be opened until the following morning. The Arab writer Usāma Ibn Munqidh described how one group of crusader cavalry dismounted outside the gate of a twelfth century castle and used their lances as pikes to defend its entrance. On another occasion, those making a sortie included men riding mules, though whether they were mounted infantry or knights who lacked proper mounts is unclear. Some Frankish garrisons defended themselves so vigorously that anyone coming within range of their walls had to wear armor.
The crusaders came to the East with a tradition of wooden siege engines, which were vulnerable to the incendiary weapons of both Byzantines and Muslims. For example, the First Crusade (1096-1099) used a wooden tower on wheels or rollers during its attack on Albara (mod. al-Bārah, Syria); it had knights on top, while other armored men pushed it forward. The Franks’ two wooden siege towers used during an attack on Tyre (mod. Soûr, Lebanon) in 1111-1112 contained rams suspended by ropes. Both were burned by the defenders. The chats châteaux (combined shelters and siege towers), used against Damietta during the crusade of King Louis IX of France to the East (1248-1254), enabled the besiegers to protect their miners attacking the base of a wall and also shoot at enemies defending the parapet of that wall. The troops inside wooden siege towers were said to have stored water and vinegar to douse fires. In turn crusader archers shot fire-arrows at the bundles of straw that defenders would hang in front of their walls as buffers against stones or rams.
Although the Franks did not use stone-throwing mangonels in such numbers as did their Muslim foes, they clearly had the latest versions, including boves, a type of mangonel with adjustable counterweights. Those defending Acre in 1291 could throw a stone whose weight has been translated as 45 kilograms (99 lb.) by some historians [D. P. Little, “The Fall of ‘Akka in 690/1291: The Muslim Version,” in Studies in Islamic History and Civilization in Honour of Professor David Ayalon, ed. M. Sharon (Leiden: Brill, 1986), pp. 159-181]. The Western European espringal was an antipersonnel weapon that came in various sizes, the best being made of beech, elm, or oak. Its torsion power was provided by twisted skeins or ropes of horse or cattle hair, and it could shoot a truly massive arrow.
The reconquest of the Iberian Peninsula (Reconquista) was primarily aimed at cities, several of which were so large or well fortified that sieges sometimes took years. Occasionally the final struggle was resolved by street fighting of almost modern savagery. Siege engineering in the Christian states of northern Iberia was, of course, greatly influenced by that of the Muslim south. For example, the Spanish algar- rada came from the Arabic al-‘arrāda, which was a small antipersonnel mangonel. The manganell turquès (“Turkish mangonel”) mentioned in early thirteenth-century Aragon was probably a new form, perhaps with an adjustable counterweight.
Muslim armies used various siege techniques. Light troops went ahead to impose a blockade, and orchards outside the city were progressively destroyed in an attempt to induce surrender, while the besiegers defended themselves with palisades and entrenchments. A thirteenth-century military manual by the writer al-Harawi, based upon long established procedures, lists the sequence of events as follows: First the commander ordered his laborers to assemble siege machines. Then bombardment began with the smallest engines, followed by those of greater power to put the enemy under increasing psychological pressure. The besiegers were also to post units of cavalry an arrow-shot from each enemy gate as a precaution against sorties.
Saladin’s siege train included a variety of specialist troops such as engineers, fire troops, flamethrower operators, surveyors, and assorted craftsmen. It is also clear that the Muslims did more mining than crusader or Frankish armies, and they used the originally Chinese tactic of erecting mounds of earth as firing positions for stone-throwing machines throughout the medieval period and well into the early modern era. Such machines gradually demolished the enemy’s battlements so that defending archers lacked cover. Assault parties were commanded by the best officers, while the troops themselves carried fire weapons and tools to further demolish the enemy wall. A further variation was to use any numerical advantage to make small attacks against different parts of the wall and thus exhaust the garrison.
In defense, Muslim garrisons resorted to various stratagems, including psychological warfare: for example, they sent men with torches out of a postern gate by night, who then returned with their torches extinguished and emerged again, making the garrison appear more formidable. Local militias used their knowledge of surrounding orchards and gardens to destroy small groups of invaders, as happened during the crusader attack on Damascus in 1148. During the siege of Acre in the course of the Third Crusade, the son of a coppersmith surpassed professional fire-troops by designing a more effective way of shooting Greek Fire (the petroleum-based incendiary liquid, which is still widely, though perhaps wrongly, regarded as the “secret weapon” that enabled the Byzantine Empire to survive against repeated Arab-Muslim attacks during the early medieval period), thereby destroying the crusaders’ siege engines. During this same siege, the defenders also used a grappling hook to ensnare one of the leading men in the army of Richard the Lionheart, hauling him up the wall.
The counterweight mangonel, or trebuchet, is generally considered to have been invented in the Middle East during the twelfth century, though there is evidence that a primitive counterweight manjamq had been known in the Muslim area two centuries earlier. This “Persian” weapon was first illustrated and described in a military treatise written by Murdā al-Tarsūsī for Saladin. Nevertheless, the counterweight trebuchet did not have a major impact on siege warfare until the start of the thirteenth century.
Al-Tarsūsī also described well-established forms of man- powered manjaniqs, of which the “Arab” type was considered most reliable. It consisted of a wooden frame with a roof and three walls to protect a team of rope-pullers inside. The “Turkish” type required less timber and was simpler to erect, while the “Frankish” or “Rūmī” (i.e., Western or Byzantine) version had a more stable arm and axle. The smallest form (Arab. lu’ab) was mounted on a single pole and had the smallest payload and shortest range, but could shoot in any direction. By the late thirteenth century, some of the largest counterweight machines were prefabricated and transported to the scene of a siege in pieces. As elsewhere, most mangonels and other siege engines could also be used defensively from the top of fortified towers.
Apart from unclear references to a “black bull-like” man- janiq that shot large arrows rather than stones, and may therefore not have been a beam-sling weapon at all, there were several bolt-shooting machines. These included the great crossbow, which was sometimes mounted on a frame or pedestal. This weapon had been known for centuries; it was spanned by a windlass or other mechanical means. The qaws al-ziyār, known in Europe as the espringal, was another fearsome weapon spanned by a winch or windlass. It had two separate “bow arms” thrust through tightly twisted skeins of animal hair, silk, sinew, or a mixture of these. The monstrous version described by al-Tarsûsi had the power of twenty men, but even in fourteenth-century Morocco, it took eleven mules to carry a dismantled qaws al-ziyār. The ordinary ziyār appears to have been a development of the single-armed stone-throwing engine known in Late Roman times as an onager.
Mobile wooden sheds to protect men working rams were used by Islamic armies, as they were by crusader and Byzantine forces, but, like the burj (wooden siege tower), were ideal targets for Greek Fire and other forms of fire weapon. Perhaps for this reason, they largely fell out of use from the late thirteenth century. Other more common devices were screens and mantlets to protect sappers and miners, which were commonly used by virtually all medieval armies. One example used during the final siege of Acre by the Mamlûks in 1291 consisted of a large sheet of felt on a system of pulleys. It not only hid individual men but absorbed mangonel stones and crossbow bolts. The zahafah is more obscure, but may have been a fixed immobile wooden tower for archers.
Fire weapons became steadily more effective. In twelfth- century Syria, for example, clay and glass grenades were designed for different purposes, some apparently being antipersonnel weapons. Yet the decline of fire weapons from the end of the fourteenth century may have resulted from their own success in driving wooden and other inflammable targets from the battlefield.
Siege technology in the western Muslim world was virtually identical to that in the Near and Middle East and became particularly sophisticated under the Almohads in the later twelfth century. Here a commander sometimes had a mar- qaba (observation post) erected from which he could direct operations. Another notable feature of sieges in these west ern regions was the building of towns, complete with their own stone fortifications, next to the city under attack; the walls and minaret of one such “counter city” still stand at al- Mansûraoutside Tlemcen in North Africa. Otherwise the usual sequence of events was followed. Defenders fought outside their walls until convinced that the attackers could not be driven away. In fourteenth-century Granada, this stage was followed by walling up all gates except those needed for sorties. Particularly advanced semiexplosive pyrotechnics also appeared in North Africa and al-Andalus in the late thirteenth century, some of them possibly incorporating primitive gunpowder. Knowledge of saltpeter, essential in the making of gunpowder, already existed in the Middle East, and traces are said to have been found in ceramic grenades found at the sites of thirteenth- or even twelfth-century sieges. It was not, however, until the fourteenth century that gunpowder was used widely in siege warfare, not only in primitive guns but as rockets and as an incendiary substance.