Medieval Siege Weapons: Tools of Castle Warfare

Throughout the Middle Ages, engineers and armies developed a range of siege weapons designed to break through even the strongest castle defenses. These medieval weapons ranged from simple, yet devastating tools like the battering ram, to highly engineered machines such as the trebuchet and ballista. Each device served a specific purpose — whether it was to launch projectiles over high walls, smash through gates, or provide elevated platforms for soldiers to storm fortifications. Popular examples include the mangonel, siege tower, and catapult, all of which played key roles in prolonged battles for control of fortified strongholds. This article explores the most effective and iconic castle siege weapons used during medieval warfare, revealing the ingenuity and brutality of siege tactics in this era.

A Trebuchet Catapult Siege Attack on a Castle


Ballista – Catapult Siege Weapon

The Ballista was one of the most important castle siege weapons whose shape was similar to that of a large crossbow. It worked on the same principle that a dart-throwing machine works, only on a much larger scale.

Heavy bolts, darts, and pieces of iron could be aimed at the castle with a Ballista. It was used in the ancient world as well but became widely popular during medieval times.

Ballista Siege Weapon
Ballista Siege Weapon used in ancient times

Mangonel Catapult Siege Weapon

The Mangonel was another popular castle siege weapon that was quite similar to a catapult and was used to fire heavy projectiles from a large bucket attached to it.

Mangonel Siege Weapon
Mangonel Siege Weapons outside castle grounds used to attack medieval castle walls

It had an advantage over other catapults in that its design was simpler and thus it could be constructed easily. However, the Mangonel was not as accurate in hitting its target as a Ballista. Just like a Ballista, it was used in the ancient world but became more famous during medieval times.

Mangonel Catapult Origins
The Roman Onager was an early Mangonel Catapults used by Roman Soldiers

Battering Ram – Castle Siege Weapons

Among the most common form of castle siege weapons were battering rams which could be made into various sizes and shapes. For instance, there were simple log battering rams, battering rams with flat heads, battering rams with iron or bronze heads, battering rams with actual ram’s style head, and others.

Battering Ram Siege Weapon

Sometimes a roof was used on the battering ram in order to protect the soldiers from incoming enemy missiles. This roof was called a penthouse. The use of battering rams was quite popular because they were very simple to construct and easy to operate. However, they could only be used once the castle gate had been approached.

Battering Ram Front
Image shows battering ram from the front

*Castle moats, especially if the castle had a drawbridge were a very effective defense against battering rams.


Trebuchet Catapult Type Siege Weapon

Various other kinds of castle siege weapons were also prevalent during medieval times. For instance, the Trebuchet siege Weapon was not very different from a catapult *Main difference the larger Trebuchet can throw heavy projectiles.

Trebuchet Siege Weapons
Example of a Medieval siege weapon – Trebuchet Siege Weapons

The trebuchet was mainly used to throw heavy stones at the outer walls and Gatehouses of the Castles to demolish them.

Trebuchet Siege Weapon
See The detail of this medieval Trebuchet Siege Weapon

Catapult Siege Weapon

Catapults were effective weapons during a Castle Siege attack, to break down walls, throw burning missiles, rotting carcasses, even excrement and garbage*

Types of Catapults

*The most powerful Catapults were the mangonel and trebuchet siege weapons

Mangonel Siege Weapon
Mangonel Siege Weapons outside castle grounds used to attack medieval castle walls

Mangonel Catapults were also known as the ‘traction trebuchet’ could throw heavy objects for considerable distances  *Distinctive with an arm with a large bowl shape at the end *Because of its power heavy stones could be thrown – but also rotting bodies and excrement!

Siege Weapons Castles

Trebuchet

A trebuchet could be described as a counterweight throwing engine, a kind of giant wooden sling that was mechanized. The Trebuchet has its origins in the sling that originated in ancient China but its exact date of origin is unclear.

The Trebuchet was a very powerful siege weapon that could throw very large and heavy stones some distance *Famously the legendary Warwolf was the biggest Trebuchet ever to be built in history and used during the Scottish Wars of Independence. It was built on the orders of King Edward in 1304 as he laid siege to the Stirling Castle in Scotland.

Trebuchet Siege Weapon
The Image gives you an idea of the size of a Trebuchet Siege Weapon

Onager

Mangonels were also considered to be Onagers in some circumstances, the Onager siege weapons were created before the later superior Mangonel and launched projectiles from a sling.

Siege Ascalon Knights Templar


Castle Siege Tower

The Castle Siege Tower was constructed from wood, siege towers were designed to align with the top of an enemy’s Castle walls and give attacking soldiers a way to breach the Castles walls or target battlement areas under protection.

Siege Tower and Battering Ram
Siege tower with additional weapons etc

Siege towers had small wheels that would enable them to be pushed close to castles walls, multiple siege towers could be used to overwhelm a castle’s defenses and they could also be used against damaged areas of the castle’s main walls or towers.

Roman Siege Tower
Roman Siege Tower

*Castle moats, especially if the castle had a drawbridge were a very effective defense against siege towers.


Castle Siege Weapons Summary

Castle siege weapons played a very important role in conquering a medieval castle. Without these weapons, it was almost unthinkable to defeat the army within the castle.

Famous Castle Sieges
Famous Castle Sieges

Thus, over the centuries, various new castle siege weapons were constructed with sophisticated techniques, although many of these castle siege weapons were also prevalent in ancient times. Their use, however, became particularly widespread during medieval times when a large number of castles were built.

Trebuchet Siege Weapon

Learn about the types of Trebuchet Siege Weapons used by besieging armies during a Castle Siege *Discover the Evolution and Power of the Trebuchet Siege Weapon! During medieval times Castle

5 Destructive Siege Weapons

The most destructive medieval siege weapons ever used in battle were surprisingly simple but highly effective and they were also the top medieval siege weapons around during the Middle Ages.

Siege Attack Weapons List

Medieval castles were typically protected by high and thick walls, protective towers, and men on castle walls. An army attacking a castle had to undertake different tactics and use a

Mangonel Siege Weapon

The Mangonel Siege weapon was a type of catapult used in the medieval period in siege warfare. Heavy projectiles were thrown with the help of Mangonel in order to harass

Ballista Siege Weapon

The Ballista also known as the bolt thrower was an important medieval siege weapon that was used to fire bolts or stones for long distances. This was among those medieval

Roman Siege Tower

Siege Towers

Discover how Siege Towers (Belfry) were used by besieging armies during a medieval Castle Siege.  Learn about Belfry Siege Towers’ workings and how they were used in Warfare! Siege towers