Trebuchet A trebuchet ( French " trébuchet " ) is a siege engine used in the Middle Ages . It is sometimes called a counterweight trebuchet or counterpoise trebuchet , to distinguish it from an earlier weapon called the traction trebuchet , which employed pulling men working the mechanism . The counterweight trebuchet appeared in both Christian and Muslim lands around the Mediterranean in the 12th century . It could fling projectiles weighing up to 350 pounds ( 160 kg ) at or into enemy fortifications . Its use continued into the 15th century , well after the introduction of gunpowder . The trebuchet ' s technical constructions were lost at the beginning of the 16th century . In 1984 , the French engineer Renaud Beffeyte made the first modern reconstruction of a trebuchet , based on documents from 1324 . Basic design . A trebuchet works by using the energy of a raised counterweight to throw a projectile . A long beam is attached to an axle . At the short end of the beam is attached the counter weight . The long end of the beam is pulled down , raising the counterweight . A sling , which has a pouch containing the projectile , is attached to the long end of the beam . Upon releasing the trigger , the sling and the beam swing upward , pivoting on the axle toward the vertical position , whereupon one end of the sling releases , opening the pouch and allowing the projectile to fly towards the target . The stored energy of the counterweight is transferred efficiently to the projectile . Modern - day enthusiasts have varied the original design , especially to control the path of the counterweight for increased efficiency . The three chief distinguishing characteristics of a trebuchet are : Trebuchet variations . The trebuchet is often confused with the earlier torsion siege engine s . The main difference is that a torsion siege engine ( examples of which include the onager and ballista ) uses a twisted rope or twine to provide power , whereas a trebuchet uses a counterweight , placed much closer to the fulcrum than the projectile to provide ( inverse ) mechanical advantage and thereby sweep the long arm much faster than the counterweight falls . A trebuchet also has a sling holding the projectile ( although the Roman onager often had a sling as well ) , and a means for releasing it at the right moment for maximum range . Further , the stroke finishes without the long arm slamming into a pad as with a torsion catapult producing the " kick " that prompted the name " onager " . With a trebuchet , the action of the sling captures much of the forward speed of the arm just before release of the payload as could be seen in a strobe image . The Couillard is a smaller version with a single stem or platform instead of the usual double " A " frames . The counterweight is split into two halves to avoid hitting the center stem . History . Traction trebuchet . The trebuchet derives from the ancient sling . A variation of the sling , called staff sling ( Latin : " fustibalus " ) , contained a short piece of wood to extend the arm and provide greater leverage . This evolved into the traction trebuchet in which a number of people pulled on ropes attached to the short arm of a lever that has a sling on the long arm . This type of trebuchet is smaller and has a shorter range , but is a more portable machine and has a shorter cycle time than larger , counterweight - powered types . The smallest traction trebuchets could be powered by the weight and pulling strength of one person using a single rope , but most were designed and sized for between 15 and 45 men , generally two per rope . These teams would sometimes be local citizens helping in the siege or in the defense of their town . Traction trebuchets had a range of when casting weights up to . It is believed that the first traction trebuchets were used by the Mohist s in China as early as in the 5th century BC descriptions of which can be found in the " Mojing " ( compiled in the 4th century BC ) . The Chinese named the later counterweight trebuchet Huihui Pao ( Muslim Weapons , " huihui " means Muslim ) or Xiangyang Pao ( 襄陽砲 ) , where Pao means bombard . The traction trebuchet next appeared in Byzantium . The " Strategikon " of Emperor Maurice , composed in the late 6th century , calls for " ballistae revolving in both directions , " ( Βαλλίστρας έκατηρωθεν στρεφόμενας ) , probably traction trebuchets ( Dennis 1998 , p . 99 ) . The " Miracles of St . Demetrius " , composed by John I , archbishop of Thessalonike , clearly describe traction trebuchets in the Avaro - Slav artillery : " Hanging from the back sides of these pieces of timber were slings and from the front strong ropes , by which , pulling down and releasing the sling , they propel the stones up high and with a loud noise . " ( John I 597 1 : 154 , ed . Lemerle 1979 ) They were also used with great effect by the Islamic armies during the Muslim conquests . A surviving Arab technical treatise on these machines is " Kitab Aniq fi al - Manajaniq " ( " كتاب الأنيق في المنجنيق " , " An Elegant Book on Trebuchets " ) , written in 1462 by Yusuf ibn Urunbugha al - Zaradkash . It provides detailed construction and operating information . There is some doubt as to the exact period in which traction trebuchets , or knowledge of them , reached Scandinavia . The Vikings may have known of them at a very early stage , as the monk Abbo de St . Germain reports on the siege of Paris in his epic " De bello Parisiaco " dated about 890 AD that engines of war were used . Another source mentions that Nordic people or " the Norsemen " used engines of war at the siege of Angers as early as 873 AD . Hand - trebuchet . The hand - trebuchet ( ) was a staff sling mounted on a pole using a lever mechanism to propel projectiles . Basically a portable trebuchet which could be operated by a single man , it was used by emperor Nikephoros II Phokas around 965 to disrupt enemy formations in the open field . It was also mentioned in the Taktika of general Nikephoros Ouranos ( c . 1000 ) , and listed in " De obsidione toleranda " ( author anonymous ) as a form of artillery . Counterweight trebuchet . The earliest written record of the counterweight trebuchet , much more powerful than the traction version , appears in the work of the 12th century Byzantine historian Niketas Choniates . Niketas describes a trebuchet used by Andronikos I Komnenos , future Byzantine emperor , at the siege of Zevgminon in 1165 which was equipped with a windlass , an apparatus which was required neither for traction nor hybrid trebuchets to launch missiles . Chevedden dates the invention of the new artillery type back to the Siege of Nicaea in 1097 when the Byzantine emperor Alexios I Komnenos , an ally of the besieging crusaders , was reported to have invented new pieces of heavy artillery which deviated from the conventional design and made a deep impression on everyone . The dramatic increase in military performance is for the first time reflected in historical records on the occasion of the second siege of Tyre in 1124 , when the crusaders reportedly made use of " great trebuchets " . By the 1120 – 30s , the counterweight trebuchet had diffused not only to the crusaders states , but probably also westwards to the Normans of Sicily and eastwards to the Great Seljuq s . The military use of the new gravity - powered artillery culminated in the 12th century during the Siege of Acre ( 1189 – 91 ) which saw the kings Richard I of England and Philip II of France wrestle for control of the city with Saladin ' s forces . The only pictorial evidence of a counterweight trebuchet in the 12th century comes from an Islamic scholar , Mardi bin Ali al - Tarsusi , who wrote a military manual for Saladin circa 1187 . He describes a hybrid trebuchet that he said had the same hurling power as a traction machine pulled by fifty men due to " the constant force [ of gravity ] , whereas men differ in their pulling force . " ( Showing his mechanical proficiency , Tarsusi designed his trebuchet so that as it swung it cocked a supplementary crossbow , probably to protect the engineers from attack . ) During the Crusades , Philip II of France named two of the trebuchets he used in the Siege of Acre in 1191 " God ' s Stone - Thrower " and " Bad Neighbor . " During a siege of Stirling Castle in 1304 , Edward Longshanks ordered his engineers to make a giant trebuchet for the English army , named " Warwolf " . Range and size of the weapons varied . In 1421 the future Charles VII of France commissioned a trebuchet ( " coyllar " ) that could shoot a stone of 800 kg , while in 1188 at Ashyun , rocks up to 1 , 500 kg were used . Average mass of the projectiles was probably around 50 – 100 kg , with a range of ca . 300 meters . The cycle rate could be noteworthy : at the siege of Lisbon ( 1147 ) , two engines were capable of launching a stone every 15 seconds . Also human corpses could be used on special occasion : in 1422 Prince Korybut , for example , in the siege of Karlštejn Castle shot men and manure within the enemy walls , apparently managing to spread infection among the defenders . The largest trebuchets needed exceptional quantities of timber : at the Siege of Damietta , in 1249 , Louis IX of France was able to build a stockade for the whole Crusade camp with the wood from 24 captured Egyptian trebuchets . Counterweight trebuchets do not appear with certainty in Chinese historical records until about 1268 , when the Mongols laid siege to Fancheng and Xiangyang . At the Siege of Fancheng and Xiangyang , the Mongol army , unable to capture the cities despite besieging the Song defenders for years , brought in two Persian engineers who built hinged counterweight trebuchets and soon reduced the cities to rubble , forcing the surrender of the garrison . These engines were called by the Chinese historians the Huihui Pao ( 回回砲 ) ( " huihui " means Muslim ) or Xiangyang Pao ( 襄陽砲 ) , because they were first encountered in that battle . Recent research by Paul E . Chevedden indicates that the " hui - hui pao " was actually a European design , a double - counterweight engine that had been introduced to the Levant by Holy Roman Emperor Frederick II ( 1210 – 1250 ) only shortly before . The Muslim historian Rashid - al - Din Hamadani ( 1247 ? – 1318 ) refers in his Universal History to the Mongol trebuchets used at the Song cities as " Frankish " or " European trebuchets " ( " manjaniq ifranji " or " manjaniq firanji " ) : Before that there had not been any large Frankish catapult in Cathay [ i . e . China ] , but Talib , a catapult - maker from this land , had gone to Baalbek and Damascus , and his sons Abubakr , Ibrahim , and Muhammad , and his employees made seven large catapults and set out to conquer the city [ Sayan Fu or Hsiang - yang fu = modern Xiangfan ] . With the introduction of gunpowder , the trebuchet lost its place as the siege engine of choice to the cannon . Trebuchets were used both at the siege of Burgos ( 1475 – 1476 ) and siege of Rhodes ( 1480 ) . One of the last recorded military uses was by Hernán Cortés , at the 1521 siege of the Aztec capital Tenochtitlán . Accounts of the attack note that its use was motivated by the limited supply of gunpowder . The attempt was reportedly unsuccessful : the first projectile landed on the trebuchet itself , destroying it . In 1779 , British forces defending Gibraltar , finding that their cannons were unable to fire far enough for some purposes , constructed a trebuchet . It is unknown how successful this was : the Spanish attackers were eventually defeated , but this was largely due to a sortie . In 2013 , during the Syrian civil war , rebels were filmed using a trebuchet in the Battle of Aleppo . The trebuchet was used to lob explosives at government troops . Modern recreational use . Trebuchets are highly popular in modern times in a number of contexts . In particular , traditional models are constructed by historical re - enactment and living history enthusiasts , and others use the trebuchet as an engineering challenge , or for recreational purposes . The largest currently - functioning trebuchet in the world is the 22 - tonne machine at Warwick Castle , England . Based on historical designs , it stands 18 metres tall ( 59 ft ) and throws missiles typically 36 kg ( 80 lbs ) up to 300 metres ( 984 ft ) . It is built on the design of a similar trebuchet at Middelaldercentret in Denmark . Middelaldercentret was the first place in modern times a working trebuchet was constructed which happened in 1989 . Trebuchets are used to throw pumpkins at the annual pumpkin chunking contest held in Sussex County , Delaware , USA . The record - holder in that contest for trebuchets is the Yankee Siege II , which at the 2011 WCPC Championship tossed a pumpkin 2326 . 6 ft ( 709 . 1 metres ) . The , trebuchet flings the standard pumpkins , specified for all entries in the WCPC competition . Modern engineering thought and materials have come up with several non - traditional designs , in particular , several with " floating arms " to increase efficiency . A floating - arm trebuchet is an efficient modern variant . Rather than having an axle fixed to the frame , it is mounted on wheels that roll on a track parallel to the ground , and the counterweight is constrained to fall in a direct path downwards upon the release . This increases the proportion of energy transferred to the projectile . Even more radical designs exist which the ancients arguably would not even recognize as trebuchets . For example , " Merlin " uses no counterweight whatsoever — the weight of the machine itself is what powers this trebuchet .