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Roman Weaponry, Ancient Artillery & Siege Weapons, Catapults, Balistas, Siege Towers


The Roman Empire was built on conquests of other nations. Military strategy and strength were important for conquering new nations and keeping controlled provinces in order.

The Roman inventors were constantly trying to make new weapons and improving on older designs as the Roman Empire spread.

They 'adopted' many other military weapon designs from other nations. This allowed them to improve on the design and incorporate it into the training of their legionaires.

Weapons of mass destruction were the forerunner of all modern artillery. These machines gave support to the Roman legions as battles began or when laying in siege to a city or town.

Prior to any battle commencing, hordes of Roman engineers and slaves would chop down forests to supply them with the wood they would need to construct their artillery pieces.

The catapults were to heavy to pull to the next engagement with the enemy. Once a battle or siege was over, most of the larger machinery was just left where it was.

Depiction of the original 'bent bow' catapult

Depiction of the original 'bent bow' catapult


The original catapults were said to of been invented by the Greeks. During battles with the Greeks approximately 300 BC, the Romans studied the Greek catapults and began to design their own.

The original catapults were used against troops, and could even be lifted by hand to various points along the battle lines. The firing mechanism was similar to firing a crossbow and the rocks were said to be the size of a small football. The catapult was erected on a wooden pole to steady the machine whilst firing.

Torsion catapults came about in the later half of the fourth century. Even these began as small machines which were designed to stop troops from charging or bombarding enemy positions with small chunks of rock.

Roman Catapults In Action

Torsion catapults could fire rocks weighing up to 80 kilograms ( 175 pounds). The catapult, also called onager or mangonel, was generally used when a siege was taking place.

Below is a translated script which is the most detailed description of a type of catapult to of survived since the Roman era. Written by Ammianus Marcellius in the 4th century AD.


The design of the scorpion, which they now call the onager, is as follows. Two beams of oak or holm-oak are fashioned and given a moderate curvature so that they seem to bulge into humps, and the beams are connected as in a frame saw, having quite large holes bored in each side; between these beams, through the holes, powerful ropes are stretched, preventing the structure from falling apart.

From the middle of the cords a wooden arm rises at an angle and, being set upright in the manner of a yoke-pole, is so inserted in the twists of sinew that it can be raised higher and lowered; to its tip iron hooks are fastened, from hangs a sling of two or iron. A huge buffer is padded in front of the arm, a sack stuffed with fine chaff, secured by strong binding. The engine is placed on piles of turf or brick platforms.

You see, if put on a stone wall, a mass of this sort smashes whatever it finds underneath because of the violent recoil, not its weight. When it comes to combat, a round stone is put in the sling and four young stalwarts on each side, by pulling rearwards the bars to which the withdrawal ropes are connected, draw the arm down almost horizontal; finally, when all this has been done, and only then, the master artilleryman, standing loftily beside it, strikes the pin, which secures the ropes of the whole machine, with a heavy hammer; whereupon the arm, released by the sharp blow and meeting the softness of the sack, projects the stone which will smash whatever it hits.

It is called a torsion engine because its whole power is derived from torsion, and scorpion because it has an upraised sting; modern times have also applied the name of onager to it because wild asses, when hunted in the chase, throw up stones so high behind their backs by kicking that they penetrate the chests or their pursuers or actually break their bones and smash their skulls.


Many different designs and variations of Roman military artillery were used according to the individual engineers which under construction.

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Modern movies depict catapults with buckets or troughs filled with rocks, whereas some had slings instead. The sling at the end could actually throw the rocks further than the trough style catapult.

The terms 'onagar' and 'scorpion' were given to various catapults for the way they looked. The sling shot looked similar to a scorpions tail and the way it kicked up dust whilst firing resembled a donkeys hind foot kicking up dust.

When horse rope was in short supply during a Roman campaign, soldiers, slave and captives were made to shave their heads. The hair was then woven into human hair rope to form the torsion rope. Hair is actually pound for pound, stronger than steel and is much more flexible.

Collection of Catapult Missiles

Collection of Catapult Missiles

Reconstructed Siege Catapult

Reconstructed Siege Catapult

Siege catapults were monstrous machines and no two were the same. Distances the catapults fired their missiles were dependent upon torsion and timber strength plus the weight of the missile.

Historians differ in conclusion as to how far missiles were hurled, but the outcome of a barrage by these machines were devastating. The impact of a rock weighing a quarter of a ton thrown from a catapult may resemble the impact of a freight train hitting a building.

Cities under siege could face months of constant barrage by catapults. This helped reduce the number of casualties within the Roman army whilst inflicting serious casualties and damage to the besieged town.

These machines could weigh in excess of 12 tonnes, be 7 - 9 meters in height, and 9 -10 meters long, and could of required over thirty men to operate it.

Catapult Facts & Summary


A torsion fired mechanism averaging 5-7 feet in length and weighing up to 400 pounds. Horse drawn for easy maneuverability. Used against wood fences, stone walls and especially against troops.

A single missile range of up to 350 feet with the most effective range being 150 feet. Mainly used in groups of many onagars against oncoming troops.


Used against castle walls and at troops. Throws several smaller missiles at a high velocity and a low trajectory. Used mainly in the field against troops where the impact area was wider causing more casualties.

Approximately 12 - 16 feet and weighing 1300 pounds and requires a firing crew of 2. Covering the missile fired with oil give the flaming balls often depicted in movies.

Maximum range is approximately 450 feet with a maximum effective range being 250 feet.



A fierce-some weapon with many variations used depending upon the battle scenario. The ballistae was a highly prized and admired weapon in the Roman army. Adopted by the Romans from Greek designs, the ballista could pick off individual soldiers like a modern day sniper.

The first Roman designed ballistas were made of wood with iron fittings. The two types of ballista were bolt or stone firing.

All missiles were fired by a bow string, similar to a crossbow. Drawing back on the drawstring allowed the tension to build up depending on the range required. All the mechanisms were controllable and could be altered depending on weather conditions and wind speed / direction.

Ballista Bolt Heads

Ballista Bolt Heads

The portability of the ballista ensured its use in every campaign. They were mounted onto ships and used to attack other ships as well as troops on beaches. Mounted in fortifications around town and cities, the ballista caused many casualties amongst attacking forces.

Firing range was approximately 460 meters with the maximum effective range 250 meters. Larger ballistas made of iron, could fire bolts measuring up to 2 meters in length impaling several troops at once.

The normal bolts used were lightweight compared to the stones of other types. Iron tipped with a wooden shaft, the bolts sailed through the air cutting down horses and troops. Ballistas were also used in riot control situations where the unruly crowd would simply be fired upon.

Office / School Warfare


This was a large ballista mounted onto a cart. Used in battle it could be used whilst moving and provided support for cohorts of legionaries Just less than 2 meters in width, this two and four wheel style of ballista helped Rome expand their empire.

Polybolos Ballistae

This is alleged to of been the machine gun of the Roman period. Said to of been able to fire up to 11 bolts per minute, making this an awesome piece of engineering. This machine has never been authenticated by historians and no remains have actually been located. But it is depicted in several modern movies.


Reconstruction of the Masada Siege Tower

Reconstruction of the Masada Siege Tower

Siege Towers

Most siege towers were constructed on-site. Each tower was meticulously constructed for height and accessibility for the troops to invade a fortified city, town or fort. They were 'disposable' military machines which usually only had a life span of one attack.

Prior to being used, many siege towers were soaked in water to help avoid them being set alight by the opposing army. Many were also covered with animal pelts or metal.

Inside the towers would be a system of ladders and small landings where troops would climb to each level and wait for the tower to reach a city wall.

There are many different types of siege tower, but they all had the same job to do, to get troops over high walls.

Inside many of the towers would be archers or ballistas' firing at the enemies troops waiting on the walls. The towers would be driven by either men or mules attached to the back and pushing it along. The gangplank would then be dropped allowing troops to rush the defenders.

The oldest siege towers used are allegedly from the 9th century BC. Defenders of cities knowing that siege towers were being built would flood the land in front of the city. This would the bog down the tower and make the soldiers inside easy targets for their archers.

Siege towers were also though to be mounted onto ships in limited circumstances. This was to attack cities whose walls were very close to the ocean. Some were even fitted with battering rams.


Battering Rams

This was a strange but very effective and life costly siege weapon. It was pushed up to the gate of a fortification and used to 'ram' open or break it.

Pushed along by as many as 100 men, the wood and metal constructed battering ram was covered on many sides with thin armaments to help protect the men. Coated in leather and water to help stop it being set on fire, the battering ram was then occasionally set on fire by the people who had been pushing it.

The idea was that once the battering ram had breached the gate, it would then burn for hours. This would destroy the gate and portcullis leaving a gaping hole for the attackers to invade the city.

The main piece of the battering ram was the log in the centre. This was suspended from a roof by ropes or chains. The tip of the log was sometimes encased in iron for better penetration.

Oil, arrows, rocks and even dead animals and humans were hurled down onto the battering ram during attacks.

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