Roman Siege Engines

Masada Epic Project by Grant He

Last updated 04 February 2015

"Roman siege machines" by the Air War college

This sketch shows the various siege engines Romans used to assault fortified towns and cities. The siege engines were divided into two large groups: artillery and wall-breakers.  Different engines were used together to achieve the greatest effect.


Artillery supported the infantry, who would focus on attacking the weakest point of the enemy's defenses. The artillery had three main goals:

  1. Cause damage to defenses
  2. Create casualties among the opposing army
  3. Destroy enemy morale

Artillery also provided cover fire for soldiers building siege ramps or those in siege towers. The most well-known artillery used by the Romans were the ballista, the onager, and the scorpio.

Ballista - Giant Crossbow

Every century (group of 60-100 men) in the Roman army had a ballista by 1st century AD. The ballista was a powerful ancient crossbow. The ballista could fire iron-tipped bolts or stone balls toward the enemy positions. It had a practical range of about 300 meters, and would be operated with about ten men.

"Ballista" by Pearson Scott Foresman

The bolts whistled through the air at 50 meters a second, and carried a terrifying punch; it would penetrate through armor and cause instant death. Some ballista stones found at Masada had been chiseled to make them as round as possible.

Onager - Catapult

The onager got its name from its kicking action - similar to that of a donkey. (also onager) It is a type of a catapult that uses torsional pressure, generally with twisted rope, to store energy for the shot. The spoke was forced down, against the tension of twisted ropes, and then suddenly released. The projectile would shoot over.

"Onager with sling" by Ralph Payne-Gallwey

The onagers were mainly used for besieging forts and settlements. They would be loaded with large stones that could be covered with a flammable substance and set on fire.

Scorpio - Dart Thrower

The Roman scorpio was a device similar to a crossbow that fired smaller arrows but with deadly accuracy. They were named after their armor-piercing sting and could be operated just by one or two men. Because of its smaller size, it could be mounted on or in siege towers. These scorpios would be used to kill or injure enemy troops, rather than to break down enemy fortifications.


The only goal of wall-breakers is to, well, breach the walls of enemy fortifications.

Battering Ram

The battering rams (also known as aires) were an extremely effective method for breaking down an enemy's walls, as well as their morale. The ram is essentially a long wooden beam with an iron end shaped in a ram's head. It is suspended with cables onto a  balance beam. It is drawn back by an enormous number of people who then pushed forward in unison with all their might so that the iron head would hit the wall. There weren't any towers strong enough nor any walls thick enough to withstand repeated blows of this kind, and many gave in on the first wave of shock.

"Meyers" from Meyers Konversationslexikons

For protection, the battering ram was suspended under the protection of a tortoise (also known as testudo); these were named tortoises because the ram would swing into and out of them like a tortoise's head coming in and out of a shell. Such shelters would defend the men manning the rams from taking fire from missiles or incendiary devices. The entire shelter would be entirely covered with fireproof materials such as uncured hides.

Fun Fact: Under Roman Law, any defenders failing to surrender before the first ram touched the wall were denied any rights. That means that the moment they heard the ram hit the wall, the people inside the city knew that the proper siege had begun, and there was no turning back.

Siege Towers

The Roman siege towers would vary in height and structure depending on the circumstances. The siege tower at Masada was 75 feet high, while the siege tower at the Battle at Jotapota (another battle against the Jewish rebels) was 50 feet high and had iron plating. It was possible to have many different devices, such as artillery, rams, and draw bridges.

Young Folks' History of Rome Illustration by Younge, Charlotte Mary


Mines could be dug under city walls in order to enter the city secretly; however, it was used more often as a way to weaken the city walls. Sappers would fire at the underpinned wooden supports with incendiary materials, causing the walls to collapse.

Works Cited

Barrow, Mandy. "Roman Artillery." Roman Artillery. N.p., 2013. Web. 2 Mar. 2015.

Campbell, Duncan B. Greek and Roman Siege Machinery 399 BC-AD 363. Vol. 78. Oxford: Osprey, 2003. Print. New Vanguard.

Cartwright, Mark. "Roman Artillery." Ancient History Encyclopedia. Ancient History Encyclopedia, 2 Feb. 2014. Web. 2 Mar. 2015.

Davies, Gwyn. Roman Siege Works. 6th ed. N.p.: Tempus, 2005. Print.

Lendering, Jona. "Wars between the Jews and Romans: The Destruction of Jerusalem (70 CE)." Wars between the Jews and Romans. Livius, n.d. Web. 02 Mar. 2015.

Levithan, Josh. Roman Siege Warfare. Ann Arbor: U of Michigan, 2013. Print.

Ricky, Bill E. "Roman Weaponry, Ancient Artillery & Siege Weapons, Catapults, Balistas, Siege Towers." HubPages. HubPages, 15 Jan. 2015. Web. 01 Mar. 2015.

Schmitz, Leonhard. "Aries." LacusCurtius • Aries. N.p., 6 Aug. 2012. Web. 2 Mar. 2015.

Comment Stream

3 years ago

Very nice work!