Medieval Ballista. Types, Facts and History

The medieval ballista was a powerful and versatile siege weapon widely used throughout the Middle Ages to breach castle walls, defend fortifications, and dominate battlefields. Evolving from ancient Greek and Roman artillery, the ballista functioned like a giant crossbow, launching heavy bolts or stones with remarkable precision and force. Over time, various types of ballistae were developed to meet specific military needs, from stationary fortress defenses to mobile battlefield artillery. This article explores the fascinating history, key facts, and different types of medieval ballistae, shedding light on their critical role in shaping medieval warfare and siege tactics.

Ballista Siege Weapon
Ballista Siege Weapon outside medieval castle

This was among those medieval siege weapons that were used in attack and siege of medieval castles. A quite sophisticated mechanism was used to operate the medieval ballista and it could be built in various sizes depending on the need.

Balista-Castle-Siege-Weapons

Ballista Siege Weapon History

Corrected Version: Ballista Siege Weapon History

The ballista was an ancient missile weapon that launched projectiles such as large arrows or stones. Its development can indeed be traced back to ancient Greece, particularly during the 4th century BCE under Dionysius I of Syracuse. Greek engineers combined features from earlier weapons:

  • The gastraphetes (a shoulder-loaded, large-scale crossbow)
  • The oxybeles (a more advanced torsion-powered bow)

These innovations led to the first versions of the ballista, which operated using torsion power (twisted ropes made of sinew or hair) to launch projectiles with great force.

Later, the Romans adopted and improved the design, using the ballista widely in military campaigns — both in sieges and on the battlefield. Roman ballistae became more standardized and powerful, often used in legions.

By the medieval period, the ballista saw declining use compared to other siege weapons like the trebuchet, but it was still employed, particularly in defensive fortifications.

Ballista Siege Weapon
Ballista Siege Weapon used in ancient times

Definition of Ballista Siege Weapon

The word Ballista is derived from the Greek word “Ballistes” which meant “to throw”. This was because of its purpose which was to throw large stones or missiles while attacking a fortification or a castle. During the early medieval times in England, ballista was also known as Ingenium which in Latin means “ingenious device”.

A Medieval Castle Being Defended Under Siege

Ballista Siege Weapon Purpose

Ballista was a very effective medieval siege weapon and was primary used by the attacking army to throw large stones in order to damage the castle walls. However, it could also be used by the defending armies to throw various missiles on the attaching armies and kill the people.  Defenders had an added advantage because they could place the ballista on the top of the castle walls and thus have better range. The attackers usually mounted it on a wagon for easier mobility.

Conwy Castle Walls Conwy
Medieval Castle Walls

Ballista Siege Weapon Design and Parts

The design of a medieval ballista was quite sophisticated with a variety of parts acting in conjunction. For instance, it had two torsion springs which were mounted in a frame and each connected with a throwing arm. The throwing arms were connected with a rope that adjusted them into the firing position. A winch was used to pull the bowstrings back. Thus for its time the ballista was a quite sophisticated medieval siege weapon.

Building a Ballista Siege Weapon

The construction of ballista as a medieval siege weapon mainly made use of wood, human hair or animal sinew, and springs. Wood was used to build the main body and the two arms of the ballista while human hair or animal sinew was used to make the ropes.

A Trebuchet Catapult Siege Attack on a Castle

The Springald Ballista – Medieval Catapults

One of the most important types of ballista, which was a supremely important medieval siege weapon, was called a springald. It was similar to a large crossbow and consisted of vertical springboard which was fixed to a timber frame at its lower end. The springboard served the function of a lever and the device was strong enough to launch missiles across hundreds of yards.

Ballista Siege Weapon Summary

Ballista was a commonly used medieval siege weapon, although its use is also found among ancient Greeks and Romans. Compared to other medieval siege weapons, Ballista was a relatively sophisticated weapon and was used to throw large missiles across hundreds of yards. It could be used by invading as well as defending armies to injure the soldiers.

  • The ballista had a sophisticated mechanism which had mounted torsion springs, a frame and a throwing arm
  • The ballista also used a wince mechanism to pull back its bowstrings
  • The ballista was usually made of strong wood, springs, hair and sinew were also used to make the ballista
  • The springald was one of the best ballista weapons invented and could launch multiple missiles at once
  • The springald ballista was very effective in was used by attacking as well as defending soldiers
knight defending castle

  • A ballista siege weapon could hurl large rocks and other objects huge distances
  • The ballista siege weapons origins can be traced all the way back to ancient Greece in the fourth century BC
  • The ballista siege weapon was very sophisticated compare to other siege weapons such as battering ram
  • The origins of the name ballista comes from the Greek word “Ballistes” which means to throw
  • The ballista also had Latin name called “ingenium” that simply meant ingenious device

What is a medieval ballista?

A medieval ballista is a large siege weapon resembling a giant crossbow, designed to launch heavy bolts or stones at enemy fortifications or troops with great accuracy and power.

How does a ballista work?

The ballista uses torsion power generated by twisted ropes or sinews to store energy. When released, this energy propels the projectile forward at high speeds.

What types of ballistae existed in medieval times?

There were several types, including stationary ballistae mounted on castle walls for defense, and mobile ballistae mounted on wheels or carriages for battlefield use. Variations also differed in size and projectile type.

How far could a medieval ballista shoot?

Depending on its size and design, a ballista could launch projectiles anywhere from 300 to 500 meters (980 to 1,640 feet).

What were ballista projectiles made of?

Projectiles typically included large iron-tipped bolts or stones designed to penetrate walls or cause damage to enemy personnel.

Who invented the ballista?

The ballista originated in ancient Greece and Rome as a form of artillery. Medieval designs evolved from these classical models with improvements in power and mobility.

Why was the ballista important in medieval warfare?

Ballistae provided armies with a long-range weapon capable of breaking fortifications, disrupting enemy formations, and defending castles effectively.

When did ballista use decline?

The use of ballistae declined with the rise of gunpowder artillery in the late medieval period, which offered greater destructive power and easier operation.