HOSPITALARIO Y LIMPIEZA DEL MATERIAL
EVALUACIÓN CLAVE
Modern siege warfare received its first non-Arab textbooks for three centuries during this time, and a substantial number of tenth-century treatises have sur- vived. The emperor leo vi (r. 886–912) was responsible for the Tactica in around 906. While much of the tone of the work relates to the primarily defensive nature of Byzantine–Arab warfare in his time, a section was devoted to siege warfare. The recommendation that the besiegers fortify themselves was a repetition of good advice dating back to the ancients. The main weapons for attack were listed as scaling ladders, rams and testudines. If the buildings in the besieged town were of wood, it was recommended to fire them with burning arrows. one of the means
1 Cedrenus, Compendium historiarum, 186–7.
2 Dennis, “Byzantine heavy artillery”, 99–113. Dennis recounts the whole known devel- opment of Byzantine siege artillery, drawing substantially on Chevedden. He is undoubt- edly correct about the mid-tenth-century application of helepolis to mean a ram (p. 103), and Leo’s actual words leave not the slightest doubt that this was what he meant, since he described its features in exact detail (Leo diaconus, Historia, 695).
of propelling these was catapults, and there was specific reference to the eilaktion as a stone thrower. Mining was one of the main means of attack.
1
The middle of the century saw works by the pseudonymous author known as hero of Byzantium (the Parangelmata poliorcetica and the Geodesia), the anony- mous De obsidione toleranda, and On skirmishing. “hero”’s is a detailed manual explaining how to construct the equipment described, giving the dimensions, and with illustrations. Much attention was paid to the correct construction of mobile wooden shelters to protect miners and sappers, and the right tools for bor- ing away at the wall. The necessary steps to ensure that such machines could be safely moved up to the foot of the wall in the first place, including filling ditches and avoiding dangers posed by caltrops, were given due attention. having arrived at the wall, the main threat to such testudines was understood to be fire. Battering rams (Plate 12) were also vital, if mining had not brought the wall down. Walls made of stone were easier to overcome, because they shattered under the impact of the ram, which should be directed upwards. Against brick walls, on the other hand, ramming would make holes rather than shatter. The chapters dealing with siege towers described the necessary proportions, and some extraordinarily com- plex machines were illustrated. This section of the text was stated by hero to be based on ancient sources (notably hero of Alexandria), which also explains the detailed description then provided of torsion artillery. hero also described and illustrated a wide range of scaling ladders of different kinds, including obviously more contemporary constructions from the top of which Greek Fire could be launched at the wall top. The writer also believed that a successful commander needed a sound knowledge of mathematics, including of “dioptric direct view- ing” in order to be able to calculate the height of the enemy wall, and offered this knowledge with much other mathematical material in his second text, Geodesia.
2
The author of De obsidione toleranda concentrated on the defenders’ viewpoint. But his argument fitted the logic of current practice. There was a concern to dig ditches and lay out traps, and to deploy stone throwers to prevent the enemy reaching the foot of the wall. In another text, thought to have been a source for De obsidione toleranda, there was wide-ranging advice : along with organising large supplies of stones and inflammables on the ramparts to repel attackers, there was advice to close the town’s bars to prevent drunkenness among the soldiers ! There was also advice on resisting mining. A line of copper objects should be placed on the ground, and an ear put to them could pick up the vibrations from underground digging, allowing the planning of a countermine.
3
The text begins with the recommendation to secure the services of mechanics, engineers, archi- tects and armourers. On skirmishing may have been commissioned by Nicephorus Phocas in the 960s. Its chapter on siege warfare gives valuable insights into the1 Leo VI, Tactica, 886–99.
2 Poliorkētika kai poliorkiai (in Greek), 210–31 ; trans. as Hero, Siegecraft, 38–43 (Parangelmata, chaps. 8–11), 47–9 (chaps. 13–14), 51–3 (chaps. 15–17), 57–61 (chap. 20 : rams), 73–85 (chaps. 30–39 : towers), 91–3 (chaps. 44–5 : torsion) ; 115 (Geodesia). Latin trans. as Hero, Liber de machinis bellicis ; necnon Liber de geodaesia (1572).
contemporary situation. reflecting the strength of frontier fortresses, it advised that some places “have no reason to fear a siege”. Those likely to be attacked needed to be provided with four months’ provisions. Because most of “our towns” were located in mountainous terrain which made close encirclement difficult, defend- ers should make night time infantry sorties to break up the siege. It was vital to destroy all local sources of food for the besiegers. This would compel them to send out foraging parties far and wide, which would be vulnerable to ambush.
1
The emperor Constantine Porphyrogenitus expressed the view that an es- sential part of the general’s equipment was books : “military manuals, books on mechanics, including siege machinery (elepoleis) and the production of missiles and other information . . . relevant to wars and sieges”.
2
The emperor Basil ii learnt about war partly by reading books, and partly through his own very substantial experience.3
Nicephorus Uranus, whose Tactica is dated to around 1000, was a serving of- ficer under Basil ii and fought against both Arabs and Bulgars. Chapter 65 deals with siege warfare. he started from the viewpoint of the attacker. he advocated raiding to deny provisions to the targeted place and demanded that all commercial traffic be stopped, a real concern because “our people sell them grain and flocks in their love of gain”. having closed in on the target, the first job was to establish camp where there was a water supply, then dig an exterior trench and lay down caltrops. In keeping with what appears to have been standard practice, the advice was then to offer good terms to the defenders, who could keep their possessions as well as their lives. If they refused to surrender, different terms could be offered to different groups within the town, in order to sow dissension. The next step was for the whole army to prepare laisai : screens of vines or willow or mulberry trees, woven together in the shape of a house, with a pitched roof and able to cover up to twenty men. These should be fixed close enough to the wall to bombard the enemy with bows and slings, while others attack with sledgehammers and rams. Nicephorus also gave detailed instructions on mining. having found a good place, one should erect timber frames and mats made from branches to secure the exca- vation if the soil was loose. The tunnel needed to be deep in case the enemy had “secretly dug a counter tunnel”. he states that previous writers had recommended all sorts of different weaponry, but he had tried them all and found that under- mining was the most effective.
4
Nicephorus might also have been the author of a treatise on Campaign organi- zation and tactics, probably written in the 990s, and dealing specifically with con- ditions in the Balkans. looking at the problem from the opposite point of view from the writer of On skirmishing, this author pointed out that it was very difficult for an army to carry more than 24 days’ provisions with it, so if there was to be a siege, it was essential to assure communications through the mountain passes for supplies. Whereas campaigning against the Muslims involved territories that
1 On skirmishing, 213, 225.
2 Constantine, Three treatises, 106–7. 3 Psellus, Fourteen Byzantine rulers, 46. 4 Nicephorus Uranus, Taktika, 157–63.
were fertile and prosperous, fighting against the Bulgars was very hard, because “there is a total lack of necessities”. The besiegers’ camp needed to be just the right distance from the walls, too far to be hit by the garrisons’ throwing machines, close enough to protect one’s own siege engines from sorties. The engines needed to be set up at once, opposite the weakest points in the defences, so that the pre- cious provisions were not wasted by delays. The writer refers to his own personal experience of ruses, whereby the defenders were enticed into sorties to destroy the siege engines and were then themselves ambushed. listing all the engines and de- vices available to besiegers, he refers readers to other and ancient authorities who have dealt with them thoroughly already.
1
There has been debate as to whether these treatises actually represented the practice of their age, or whether they only reflected the work of ancient authors. leo, for example, certainly called on the work of Philo, onasander and of course Maurice, while references have been found in other texts to ancient works by Biton, Apollodorus, Aineias “the tactician” and hero of Alexandria. however, it was not surprising that the store of classical knowledge should be called upon, as many of the principles and lessons of warfare had changed very little : the authors of On skirmishing and Campaign organization and tactics explicitly said so. But the tenth-century texts used descriptive terms, and referred to events, and enemies, of their own century. The illustrations that appear in the surviving manuscripts of the eleventh century were largely of contemporary, not ancient, siege equipment and weaponry. For example, we find drawings of lever-based artillery, not the tor- sion artillery of the romans (not illustrated although described by hero), and of Greek Fire being propelled from siphons. There can be no doubt that these texts were written for the use of contemporaries and that they were useful precisely because they drew basic principles from ancient sources, but updated them in light of experience and their recommendations were followed by educated and literate generals.