Siege Warfare

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In the Medieval period besieging armies used a wide variety of
 siege engines including: scaling ladders; battering rams; siege
 towers and various types of catapults such as the mangonel, onager,
 ballista, and trebuchet. Siege techniques also included mining.

Advances in the prosecution of sieges encouraged the development
 of a variety of defensive counter-measures. In particular, medieval
 fortifications became progressively stronger — for example,
 the advent of the concentric castle from the period of the Crusades
 — and more dangerous to attackers as witnessed by the increasing
 use of machicolations and murder-holes, as well the preparation
 of hot or incendiary substances. Arrow slits, concealed doors for
 sallies, and deep water wells were also integral to resisting siege.

 Designers of castles paid particular attention to defending entrances,
 protecting gates with drawbridges, portcullises and barbicans. Wet
 skins of freshly slaughtered animals were draped over gates, hourdes
 and other wooden structures to retard fire. Moats and other water
 defences, whether natural or augmented, were also vital to defenders.

 In the European Middle Ages, virtually all large cities had city
 walls. Carcassonne and Dubrovnik in Dalmatia are well-preserved
 examples. The more important cities had citadels, forts or castles
 inside them, often built against the city walls. Great effort was
 expended to ensure a good water supply inside the city in case of
 siege. In some cases, long tunnels were constructed to carry water
 into the city. Complex systems of underground tunnels were used
 for storage and communications in medieval cities like Tábor
 in Bohemia.

 Attackers would try to get over the walls using scaling ladders,
 siege towers called belfries, and grapples. Alternatively they could
 try to get through the doors using a battering ram, or through the
 walls using heavy artillery. They might try tunnelling under the
 walls to gain access, but more often they would try to undermine
 the walls to bring them down.

 In a siege one army typically attacks an enemy within a stronghold.
 either a castle or a fortified town. Medieval towns were generally
 surrounded by defensive walls, just like castles. Indeed the distinction
 between castles and fortified towns is often blurred. Castles were
 often located within fortified towns - in fact many towns grew up
 around existing castles - so that the castle became a sort of citadel
 within the fortified town.

Attackers therefore often had two sets of obstacles - first the
 city walls, then the castle walls. This could lead to interesting
 complications as at Beaucaire in 1216. For months Simon de Montfort
 besieged Raymondet in the town, while Raymondet besieged a garrison
 loyal to de Montfort in the castle within the town.

Sometimes there were three sets of obstacles, because fauxburgs
 with their own defensive walls were often built on to the exterior
 of city walls, as at Carcassonne
 and Termes.

Besiegers had a number of techniques for gaining control of their
 objective - either by forcing a way in, or by forcing the besieged
 garrison out. Specific techniques - established since prehistoric
 times - include:

1. B**reaching the walls or doorways**. Attackers would use weapons to get through walls. Examples are stone throwing machines

 petriers such as trebuchets and mangonels); machines to knock
 holes in walls such as battering rams; and engines to extract
 individual dressed stones one by one (cats, weasels and simple
 picks).

1. T**unelling under the walls.** Attackers would build mines, either to gain access to the interior or to undermine and collapse

 the defensive walls.

1. G**etting over the walls.** Attackers would use scaling ladders and siege engines such as large mobile wooden towers known as

 belfries.

1. S**itting and waiting.** If communications between the besieged and the outside world could be cut then the defenders could be

 denied food supplies and sometimes water (as at Beaucaire, Carcassonne,
 Minerve,
 and Termes).
 This was not always possible (as for Raymondet at Beaucaire and
 at Montsegur). The word siege means "to sit", an indication
 that this was a standard technique.

1. **A Fifth Column**. Inducing someone on the inside to assist the attackers, either by bribery or exploiting divided loyalties.

 They could for example open a postern gate at night. Occasionally
 attackers could be smuggled in to the besieged fortification to
 fulfil this role, as for example in ancient times in the famous
 Trojan horse.

1. **Diplomacy, threats, terror and psychological techniques.** To help weaken the will of the defenders, attackers could make threats or promises, or terrorise the defenders - for example

 by mutilating or executing hostages, or by using throwing machines
 to lob fire, or human heads or other body parts, into the the
 fortification.

1. **Biological Warfare.** Medieval besiegers were known to project diseased animals into fortifications with the deliberate

 intention of spreading disease and so weakening the garisson.
 I some cases it was possible to poison water supplies, though
 most fortifications had their own wells or water cisterns.
 Until the invention of gunpowder-based weapons (and the resulting
 higher-velocity projectiles), the balance of power and logistics
 definitely favoured the defender. With the invention of gunpowder,
 the traditional methods of defence became less and less effective
 against a determined siege, giving rise to a new form of defensive
 structure, the star-fort.

## Siege Towers

The medieval belfry was not a church tower, but a siege
 engine - the modern meaning seemsto have come about by the
 erroneous association of towers and bells (etymologically,
 the bel in belfry is not connected with the word "bell").

A belfry was used for gaining access to a castle, generally
 at the level of the battlements. It was typically constructed
 in wood, on several stories - as many as necessary to reach
 the battlements. Each story offered a location for attack
 - bows and crossbows in the lower levels, and armed men in
 the upper level, ready to drop a sort of drawbridge and gain
 access to the castle ramparts. The belfry was normally wheeled,
 so that it could be moved up against the castle walls, and
 like all exposed wooden engines of war it would be covered
 in the hides of freshly slaughtered animals and regularly
 dowsed in water to keep it fireproof.

One way to foil the approach of a belfry was to have sloping
 castle walls. This forced the attackers to cover a greater
 distance from the top of the belfry to the top of the castle
 wall. This was one of the benefits of a talus.

 Another way to foil the approach was to build ditches and
 moats to prevent the approach of belfries.

 As on the right, attackers often needed to fill up the ditch
 or moat to provide a level surface that extended all the way
 to the foot of the castle wall.

 In practice, all sorts of material was used for this: earth,
 rocks, straw, dead bodies, wood, whatever came to hand. If
 too much wood was used in the infill then the infill itself
 became a target for fire setters.

## Battering Rams

A battering ram is a siege engine originating in ancient times
 to breach fortification walls or doors. In its simplest form, a
 battering ram is just a large, heavy log carried by several people
 and propelled with force against the target, the momentum of the
 ram damaging the target.

 Some battering rams were supported by rollers. This gave the ram
 much greater travel so that it could achieve a greater speed before
 striking its target and was therefore more destructive. Such a ram
 was used by Alexander the Great

 In a more sophisticated design, the ram was slung from a wheeled
 support frame so that it could be much more massive and also more
 easily swung against its target. Sometimes the ram's attacking point
 would be reinforced with a metal head. A capped ram is a battering
 ram that has an accessory at the head (usually made of iron or steel,
 traditionally shaped into the head and horns of a ram to do more
 damage to a building.

 Many battering rams had protective roofs and side-screens covered
 in materials, often fresh wet hides to prevent the ram being set
 on fire, as well as to protect the ram's operators of the ram from
 enemies firing arrows down on them.

 An image of an Assyrian battering ram shows how sophisticated attack
 and defence had come by the 9th century BC. In the image defenders
 are trying to set the ram alight with torches and have also put
 a chain under the ram. The attackers are trying to pull on the chain
 to free the ram - the same scene could have been depicted in Roman,
 Visigothic or Medieval times.

 When a castle was being attacked, defenders attempted to foil battering
 rams by dropping obstacles in front of the ram just before it hit
 a wall, using grappling hooks to immobilize the log, setting the
 ram on fire, or sallying out to attack the ram. Battering rams had
 an important effect on the evolution of defensive walls
 - the talus for example was one way of reinforcing walls. In
 practice, wooden gates would generally offer the easiest targets.

Raymondet,
 the future Raymond
 VII, Count of Toulouse, used a ram at Beaucaire
 in 1216. He was himself besieged in the town by Simon
 de Montfort's Crusader
 forces, while he himself was besieging the garisson of the castle
 within the fortified town. The The
 Song of the Crusade (the Canso) tells us a little about the
 ram. We know for example that it had an iron head. The poet tells
 us that it was:

*"... long, straight, sharp and shod with iron; it thrust,*
 carved and smashed till the wall was breached and many of the
 dressed stones thrown down. When the besieged Crusaders
 saw that, they did not panic but made a rope lasso and used a
 device to fling it so that they caught and held the ram's head,
 to the rage of all in Beaucaire.

*Then the engineer who had set up the battering ram arrived. He*
 and his men slipped secretly into the rock itself [presumably
 the hole already made by the ram, intending to break through the
 wall with their sharp picks. But when the men in the keep realised
 this, they cast down fire, sulphur and tow together in a piece
 of cloth and let it down on a chain.

*When the fire caught and the sulphur ran, the flames and stench*
 so stupefied them that not one of them could stay there. Then
 they used their stone throwers and broke down the beams and palisades."
 (The
 Song of the Crusade, laisse 164).

## The Cat

A Cat was a wooden structure built (or moved) up to a defensive
 wall. From surviving documents it seems that an arm could manipulated
 to claw away at the castle wall - hence the name.

Cats could be large multi-purpose structures, perhaps with a trebuchet
 on top and sappers operating from the protected interior.

 Cats were much feared and if they possibly could, castle defenders
 would try to destroy them by mounting sorties, by using stone throwing
 engines, or by setting fire to them.

 Like all wooden siege engines they would be routinely covered in
 the skins of freshly slaughtered animals and regularly dowsed with
 water to keep them fireproof.

 Simon
 de Montfort used a cat at the Siege
 of Beaucaire in 1216, but unsuccessfully. According to the Canso
 it had "no more effect than an enchanter's dream". It
 was "a spider's web and a sheer waste of material".

 Perhaps the most famous cat was one Simon
 built two years later, attempting to besiege the City
 of Toulouse in 1217-18. It was while protecting his cat from
 counter attack by the citizens of Toulouse that Simon
 de Montfort was struck on the head by a massive stone projectile
 from a trebuchet on the city walls, and killed instantly.

## The Weasel

A weasel was a similar sort of structure to a cat, but smaller
 and lighter. It seems to have been more manoeuvrable and used a
 spike rather than a paw to attack castle walls.

It may have taken its name from its business end looking like a
 weasel's nose, or perhaps its long thin body, or both.

 A weasel was used by the forces of Raymondet,
 the future Count
 Raymond VII of Toulouse, at Beaucaire
 in 1216 according to the The
 Song of the Crusade (*Canso*
 de la crozada*). As Simon*
 de Montfort was conducting a Council of War, a beggar burst
 in, shouting that he had seen a weasel. The weasel
 was already against the citadel wall and ready to drive a spike
 into it. The defenders were quick to react. The chief engineer hurled
 a pot of molten pitch at it, hitting it
 in exactly the right spot and it burst into flames.

## Chemical Warfare - Greek Fire

Incendiary devices were standard weapons of war. Wooden defences
 always needed protection from burning. Wet animal hides were highly
 effective against burning arrows so military engineers dedicated
 themselves to finding ways of ensuring that fires burned as long
 and as strongly as necessary to catch. All sorts of chemicals could
 be used for this purpose - petroleum, sulphur, quicklime and tar
 barrels for example.

Liquid fire is represented on Assyrian bas-reliefs. At the siege
 of Plataea in 429 BC the Spartans attempted to burn the town by
 piling up against the walls wood saturated with pitch and sulphur
 and setting it on fire, and at the siege of Delium in 424 BC a cauldron
 containing pitch, sulphur and burning charcoal was placed against
 the walls. A century later Aeneas Tacticus mentions a mixture of
 sulphur, pitch, charcoal, incense and tow packed in wooden vessels,
 ignited and thrown onto the decks of enemy ships. Formulae given
 by Vegetius around AD 350 add naphtha or petroleum. Some nine centuries
 later the same substances are found and later recipes include saltpetre
 and turpentine make their appearance. The ultimate in this form
 of chemical warfare was called Greek-Fire.

 Greek fire was a burning-liquid used as a weapon of war by the
 Byzantines, and also by Arabs, Chinese, and Mongols. Incendiary
 weapons had been in use for centuries: petroleum and sulphur had
 both been in use since the early days of the Christianity. Greek
 fire was vastly more potent. Similar to modern napalm, it would
 adhere to surfaces, ignite upon contact, and could not be extinguished
 by water alone.

 Byzantines used it in naval battles to great effect because it
 burned on water. It was responsible for numerous Byzantine military
 victories on land as well as at sea - and also for enemies preferring
 discretion to valour so that many battles never took place at all.
 It was the ultimate deterrent of the time, and helps explain the
 Byzantine Empire's survival until 1453. There was no defence. As
 the Lord of Joinville noted in the thirteenth century "Every
 time they hurl the fire at us, we go down on our elbows and knees,
 and beseech Our Lord to save us from this danger." Men were
 known to simply flee their posts rather than face Greek Fire. On
 the other hand Greek fire was very hard to control, and it would
 often accidentally set Byzantine ships ablaze.

 Greek Fire is said to have been invented by a Syrian Engineer,
 one Callinicus or Kallinikos, a refugee from Maalbek, or an architect
 from Heliopolis in the Byzantine Province of Judaea, in the seventh
 century (673 AD). The formula for Greek fire was a closely guarded
 secret and it remains a mystery to this day.

 The term Greek Fire was not attributed to it until the time of
 the European Crusades. Some of the original names include *Liquid*
 Fire*,* Marine Fire*,* Artificial Fire *and* Roman
 Fire*. (Muslims against whom the weapon was used called the Byzantines*
 Romans).

 The weapon was first used by the Byzantine navy, and the most common
 method of deployment was to squirt it through a large bronze tube
 onto enemy ships. Usually the mixture would be stored in heated,
 pressurised barrels and projected through the tube by some sort
 of pump, operators being protected behind large iron shields. Byzantines
 used Greek Fire only rarely, apparently out of fear that the secret
 mixture might fall into enemy hands. The loss of the secret would
 be a greater loss to Byzantium then the loss of any single battle.

 In 678 the Byzantines utterly destroyed a Muslim fleet - over 30,000
 men were lost. In 717-718 Caliph Suleiman attacked Constantinople
 (Byzantium). Most of the Muslim fleet was once again destroyed by
 Greek Fire, and the Caliph was forced to flee. There is virtually
 no documentation of its usage after this time by the Byzantines
 and it is generally believed that it was during this era that the
 secret of creating Greek Fire was lost. Formulae used after this
 date never seems to have had the same devastating effect.

 Some form of Greek Fire continued to be used for centuries. Byzantines
 used it against the Venetians during the Fourth Crusade. A so-called
 "carcass composition" containing sulphur, tallow, rosin,
 turpentine, saltpetre and antimony, became known to the Crusaders
 as Greek fire but is more correctly called wildfire.

 So far, no-one has been able to recreate Greek Fire. Arabian armies,
 who eventually created their own version sometime between the mid-seventh
 century and the early tenth. It was relatively weak copy of the
 original Byzantine substance, though still one of the most devastating
 weapons of the period. Arabs used the Greek Fire much like Byzantines,
 using brass tubes mounted aboard ships or on castle walls. They
 also filled jars with it, to be hurled by hand at their opponents.
 Arrows and javelins would be used to carry the mixture further and
 engines of war could be used to throw larger amounts over castle
 walls.

 As a defence, water alone was ineffective. On land sand could
 be used to stop the burning . Intriguingly it is also known that
 vinegar and urine were effective - suggesting an alkaline composition
 that could be neutralised by acid. According to some accounts pure
 or salt water served to intensify the burning, suggesting that Greek
 Fire may have been a 'thermite-like' reaction, perhaps involving
 quicklime. According to some sources, Greek Fire burst into flames
 on contact with water. Some have suggested phosphorus, Others have
 suggested a form of naphtha or another low-density liquid hydrocarbon
 (petroleum was already known in the East). There are numerous candidates
 including liquid petroleum, naphtha, burning pitch, sulphur, resin,
 quicklime and bitumen, along with a hypothetical unknown "secret
 ingredient". The exact composition is unlikely ever to be deduced
 from the inadequate surviving records.

 It is not clear from contemporary reports if the operator ignited
 the mixture with a flame as it emerged from the syringe, or if it
 ignited spontaneously on contact with water or air. If the latter
 is the case, it is possible that the active ingredient was calcium
 phosphide, made by heating lime, bones, and charcoal. On contact
 with water, calcium phosphide releases phosphine, which ignites
 spontaneously. The reaction of quicklime with water also creates
 enough heat to ignite hydrocarbons, especially if an oxidiser such
 as saltpetre is present.

 Ingredients were apparently preheated in a cauldron, and then pumped
 through a pump or used in hand grenades. If a pyrophoric reaction
 was involved, perhaps these grenades contained chambers for the
 fluids, which mixed and ignited when the vessel broke on impact
 with the target.

==

Biological Weapons ==
Medieval warriors also used basic biological weapons, for example
 catapulting dead and diseased animals into a defended fortress to
 help spread disease.

## Psychological Weapons

Ancient armies had used sophisticated psychological weapons. For
 example would have mad armour suitable for a man of several times
 normal size. He would then leave a few samples laying around the
 scene of his victories against the Persians. After he had gone Persians
 would find this armour and were were soon spreading stories of Alexander's
 superhuman giant soldiers.
 Christendom did not stretch to this level of sophistication, but
 it did engage in some psychological warfare, spreading rumours for
 example, sometimes with success effectively turning a military defeat
 into a political victory. Other examples of psychological warfare
 include making loud noises (an old Celtic practice) and catapulting
 the severed heads of captured enemies back into the enemy camp.

 Defenders in castles under siege might prop up dummies beside the
 walls to make it look like there were more defenders than there
 really were. They might throw food from the walls to show besiegers
 that provisions were plentiful (Dame Carcas, who saw off the Franks,
 supposedly gave her name to Carcassonne after feeding the last few
 scraps of food in the besieged city to the last pig and then tossing
 over the walls as a present to the Franks. As intended, they deduced
 that their siege was useless and raised it the next day).

 Firearms provided a strong psychological benefit when they were
 introduced, even though their rate of fire rendered them almost
 useless - and their users often blew themselves up rather than the
 enemy - literally hoist by their own petard.

## Mining, Undermining Defensive Walls

A"mine" was a tunnel dug to destabilise and bring down
 castles and other fortifications. The technique could be used only
 when the fortification was not built on solid rock. It was developed
 as a response to stone built castles that could not be burned like
 earlier-style wooden forts.

A tunnel would be excavated under the outer defences either to
 provide access into the fortification or more often to collapse
 the walls. These tunnels were supported by temporary wooden props
 as the digging progressed, just as in any mine. Once the excavation
 was complete, the mine was filled with combustible material. When
 lit it would burn away the props leaving the structure above unsupported
 and liable to collapse.

 To save effort attackers would start the digging as near as possible
 to the wall or tower to be undermined. This exposed the sappers
 to enemy fire so it was necessary to provide some sort of defence.
 Pierre
 des Vaux de Cernay recounts that at the siege of Carcassonne
 in 1209, during the Cathar
 wars (Albigensian Crusade),

>  "... after the top of the wall had been somewhat
>
>
>  weakened by bombardment from petraries,
>  our engineers succeeded with great difficulty in bringing a four-wheeled
>  wagon, covered in oxhides, close to the wall, from which they set
>  to work to sap the wall" (*Historia*
>
>
>
>  Albigensis  *- Pierre des Vaux de Cernay, 53).*
>
>

 Successful sapping usually ended the battle since either the defenders
 would no longer be able to defend and surrender, or the attackers
 would simply charge in and engage the defenders in close combat.

 There were several methods to resist under mining. Often the siting
 of a castle would be such as to make mining difficult. The walls
 of a castle could be constructed either on solid rock or water-logged
 land making it difficult to dig mines. A very deep ditch or moat
 could be constructed in front of the walls, or even an artificial.
 This makes it more difficult to dig a mine and even if a breach
 is made the ditch or moat makes exploiting the breach difficult.

 The defenders could also dig counter mines. From these they could
 then either dig into the attackers tunnels and sortie into them
 to either kill the sappers or to set fire to the pit-props to collapse
 the attackers' tunnel. Alternatively they could undermine the attackers'
 tunnel to collapse it.

 If the walls were breached they could either place obstacles in
 the breach for example a chevaux de frise to hinder an attack, or
 construct a coupure.

 The practice has left us reminders in English. "undermining"
 has acquired figurative as well as literal meanings. And military
 engineers are still known as Sappers.