Catapult

• 1. Introduction

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  The catapult is a device that changed the calculus of war long before gunpowder existed. At the siege of Motya in 397 BC, a Greek army turned a newly invented arrow-firing machine against a key Carthaginian stronghold in Sicily. It was among the first recorded uses of a weapon that would go on to reshape how armies attacked walls, defended cities, and projected power across centuries.

  At its core, the catapult works by storing energy slowly and releasing it all at once. Springs, twisted rope, bent bows, elastic materials: each method builds tension or torsion in the machine. Then comes the sudden snap, and the payload travels farther than any arm could throw it.

  The word itself arrives through Latin from the Greek katapeltēs, built from kata, meaning "downwards", and pallō, meaning "to toss, to hurl". That Greek lineage points to something deeper. The device did not spring from a single inventor's mind but grew from centuries of accumulated craft across Greece, India, China, and the Near East. How these parallel traditions developed, and where they ultimately led, is a story that runs from the walls of ancient Jerusalem to the flight decks of modern warships.

• 2. Ancient Origins

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  King Uzziah of Judah stands among the earliest rulers documented as deploying catapult-like machines. His engineers equipped the walls of Jerusalem with devices capable of shooting great stones, a detail that places this technology in the 8th century BC. The Yajurveda mentions comparable machines under the name "Jyah" in chapter 30, verse 7.

  In India, Ajatashatru of Magadha used catapults in his campaigns against the Licchavis sometime between 484 and 468 BC, with Jaina texts recording the detail. China saw the mangonel in use somewhere between 500 and 300 BC, with the Mojing, compiled in the 4th century BC, describing the weapon in chapter 14 as capable of hurling hollowed-out logs filled with burning charcoal at enemy troops.

  Greek development took a distinct path. The historian Diodorus Siculus described a mechanical arrow-firing catapult, the katapeltikon, invented by a Greek task force in 399 BC. Diodorus is thought to have drawn on the history of Philistus, a contemporary witness to those events. The theoretical foundations caught up with practice around 200 BC, when Philo of Byzantium laid out a systematic account of belopoietics, the art of making projectiles. His central principle held that all parts of a catapult, including the weight and length of the projectile, were proportional to the size of the torsion springs. That mathematical approach signals how deeply geometry and physics had entered military thinking by that point.

• 3. Torsion, Tension, and the Gastraphetes

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  Hero of Alexandria, writing in the 1st century AD, described a weapon older than the mechanical catapult: the gastraphetes, or "belly-bow", a foot-held crossbow that could store more energy than conventional Greek bows. Hero drew on the now-lost works of the 3rd-century BC engineer Ctesibius for this account. A detailed description of the gastraphetes, with a watercolor drawing, survives in Hero's technical treatise Belopoeica.

  A third source, the writer Biton, who flourished in the 2nd century BC and whose reliability has been positively reevaluated by recent scholars, described two advanced forms of the gastraphetes. He credited both to Zopyros, an engineer from southern Italy. Zopyros has been plausibly linked to a Pythagorean of the same name active in the late 5th century BC. His bow-machines already featured a winched pull-back system and could apparently launch two missiles at once. He probably built them during the sieges of Cumae and Milet, sometime between 421 and 401 BC.

  The shift from tension to torsion was the pivotal mechanical leap. An Athenian arsenal inscription dated between 338 and 326 BC lists stored catapults using springs of sinews, the first clear evidence for torsion machines. That transition was likely driven by engineers working under Philip II of Macedonia. Torsion catapults proved more powerful than flexible crossbow-style devices and came to dominate Greek and Roman artillery design from that point forward. A later Athenian inventory from 330 to 329 BC already lists catapult bolts with heads and flights, showing how quickly the technology was standardized.

• 4. Medieval Machines

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  The Viking siege of Paris in 885-886 AD put the full arsenal of classical siege craft to the test. Both attacking and defending forces deployed virtually every catapult type known to the ancient world, and the effort failed. That outcome captures something important about the medieval arms race between siege weapons and fortification.

  Of the machines fielded in that era, the ballista resembled a giant crossbow powered by torsion. Its projectiles were large wooden arrows tipped with iron, fired on a flat trajectory. Accurate but relatively low in raw firepower, ballistae were typically built on-site after a siege commander assessed the target.

  The mangonel worked differently, throwing projectiles from a bowl-shaped bucket at the end of its arm. Its range reached up to 1,300 ft, and its ammunition was remarkably varied: stones, excrement, and rotting carcasses were all recorded payloads. The word onager, sometimes used interchangeably with mangonel, comes from the Greek onagros for "wild ass", a reference to the kicking motion the machine produced. The most detailed account of the onager in use comes from Eric Marsden's translation of a text by Ammianus Marcellius, written in the 4th century AD.

  The trebuchet stood above all other medieval catapults in raw power. It came in two forms: traction trebuchets powered by teams of people, and counterpoise trebuchets where a heavy counterweight replaced the human crews. The most famous account of trebuchet use centers on the siege of Stirling Castle in 1304, when the army of Edward I built a giant trebuchet called Warwolf. Contemporary records describe it leveling a section of castle wall and concluding the siege. Incendiary payloads, including Greek Fire, were among the trebuchet's most effective munitions.

• 5. Leonardo and Later Innovation

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  Leonardo da Vinci approached the catapult as an engineering challenge to improve efficiency and extend range. His design used a large wooden leaf spring as an energy accumulator. Both ends of the bow were connected by a rope, wound around a drum. The catapult's arm attached to that drum, which was turned until deformation of the spring stored enough potential energy. When the drum disengaged from the winding mechanism, the arm snapped around and released the payload.

  No records exist of this design being built during Leonardo's lifetime. Contemporary enthusiasts have since reconstructed it.

  By the time vulcanized rubber became available in the 1840s, the catapult's military era was winding down, but its social life was just beginning. Rubber-powered hand-held catapults, built from Y-shaped sticks or sold as manufactured items, became popular with children and teenagers. In the United States these devices were called slingshots. Their arrival as a children's toy represents a long descent from siege weapon to pocket-sized mischief, a shift that took roughly two thousand years.

• 6. Aircraft and Modern Military Use

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  British experiments in 1917-1919 used Fairey Campania and Short 310 single-engine floatplanes to explore catapult-assisted takeoffs from ships. Those trials succeeded where unassisted launches from wooden platforms had started to fail, as aircraft weights and speeds increased beyond what short runways could handle.

  By the 1930s, aircraft catapults were standard equipment on major warships operated by most of the leading naval powers, including battleships and cruisers as well as aircraft carriers. Some destroyers received trial installations. Merchant vessels in France and Germany also adopted catapults in that period to launch civil aircraft, used for speeding up mail deliveries or shortening flight distances when aircraft lacked the range to complete a route without assistance.

  During the Second World War, Britain faced a shortage of conventional aircraft carriers. The solution was CAM ships: merchant vessels fitted with catapults to launch Hawker Hurricane fighters against German Focke Wulf Condor maritime reconnaissance aircraft that were tracking convoy movements and attacking ships. The Hurricanes could not be recovered after launch. Each pilot either flew toward land or ditched in the open ocean.

  The requirements drawn up for the Avro Manchester heavy bomber specified that it must be capable of catapult-assisted launch. In World War I, the last large-scale army use of catapults came during trench warfare, when they threw hand grenades across no man's land into enemy positions. Small mortars eventually took over that role. In 2024, during the Gaza war, an IDF reserve unit built a trebuchet on private initiative and used it to throw firebrands over the border into Lebanon, aiming to burn undergrowth that could conceal Hezbollah fighters.

• 7. Sport, Entertainment, and Contraband

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  Small catapults called traps are still used to fling clay targets into the air for clay pigeon shooting, a sport that continues worldwide.

  In the 1990s and into the early 2000s, a trebuchet was operated first on private property and then at Middlemoor Water Park in Somerset, England, during 2001 and 2002. Paying customers were launched 100 ft through the air. A fatality at the Water Park ended the practice. A previous injury had occurred when the trebuchet was on private property. In both cases the participants failed to land on the safety net. The operators were tried for manslaughter but found not guilty; the jury observed that the fatality might have been avoided had stricter safety measures been imposed.

  Roller coasters with a catapult launch system appeared between 1977 and 1978 in Shuttle Loop installations, using a diesel engine or a dropped weight to generate the initial momentum. Flywheels and later linear motors replaced those systems.

  In January 2011, a homemade catapult was discovered near the United States-Mexico border. It had been used to smuggle cannabis, and was found 20 ft from the border fence with 4.4 lb bales of cannabis loaded and ready to launch. Pumpkin chunking competitions, in which participants use mechanical means to launch pumpkins as far as possible, round out the device's civilian afterlife, though the world record in that category is held by a pneumatic air cannon rather than any catapult design.