Roman Weapons: The Arsenal That Built an Empire

Rome, known for its architectural marvels, political systems, and profound cultural impact, was built on the foundation of one of the most formidable armed forces in history. Central to this military dominance were the sophisticated and varied weapons of Ancient Rome.

Meticulously designed and adapted over centuries, the various types of Roman weapons – including the legendary gladius sword, the famed scutum shield, and the devastatingly effective onager catapult – were created to ensure Rome’s battlefield supremacy. These weapons reflected Rome’s emphasis on discipline, organisation, and innovation, contributing to its ability to conquer vast territories across Europe, North Africa, and the Near East.

This time-trip back to ancient Rome will put the list of Roman weapons into sharp focus.

Similar in many ways to the ancient Greeks, war was one of the defining characteristics of ancient Rome. Indeed, the gates of the Temple of Janus were left open during times of war, and it’s said they were closed – signifying peace – only a handful of times, and for very short periods, during the thousand years following the temple’s construction in the eighth or seventh century BC.

Like the city itself, the weapons of Ancient Rome evolved to meet the complex needs of its armies, from the citizen-based militia of the early Roman Republic, to the meticulously organised standing armies led by some of history’s most famous military commanders, including Julius Caesar, Scipio Africanus, Marcus Vipsanius Agrippa, and Emperor Trajan.

This constant state of conflict was a catalyst for military innovation, compelling the long list of Roman weapons and tactics to be continually refined.

Ancient Rome’s military success was closely tied to the development and use of various swords that were both versatile and effective in different combat situations. The most iconic of which were the gladius and the spatha. Each had its place in the military evolution of the Republic and the Empire, reflecting the changing nature of war, tactics, and the organisation of the Roman army.

The Gladius

There are few weapons in the history of warfare as iconic – and as feared – as the gladius, perhaps the most famous of all Roman weapons. It was a short, double-edged sword around 45 – 60 cm long with a broad, tapering point designed primarily for thrusting, but also effective for slashing. The gladius was used predominantly by Roman infantrymen – known as legionaries – during both the Republic and early Empire, as its short length allowed soldiers to maintain tight formations and strike with precision during close quarters fighting. Its use began to decline in the second century AD.

The Spatha

The spatha was a longer sword, measuring around 75 – 100 cm, and was initially used predominantly by Roman cavalry. The spatha emerged during the first century BC and became more common during the late Roman Empire, especially by the third century AD by which point it had largely replaced the gladius even for infantry units. It was double-edged, similar in shape to the gladius, but with a longer reach, making it more suited for use by cavalry soldiers who needed to strike from horseback.

The Pugio

The size of the pugio – somewhere between 18 and 28 cm long – renders it more a dagger than a sword. It’s thought it was used as a sidearm, however it’s thought it was also used as a general utility tool.

In the pantheon of Roman weaponry, spears were as important as swords, shields and catapults, and the two most common were the hasta and the pilum.

The Hasta

The hasta was used in hand-to-hand combat during the early years of the Republic. It was around two metres long and was used for thrusting rather than throwing. It was phased out and gradually replaced with the pilum towards the end of the Republic.

The Pilum

The pilum became the signature throwing spear of the Roman legions. It was introduced around the fourth century BC and remained in use after the end of the Republic, becoming one of the most important of the Roman Empire weapons. It was around two metres long with an iron shank that was very cleverly designed to bend on impact, rendering it impossible to throw back with any degree of effectiveness. Its two main purposes were to disrupt enemy formations before close engagement began, and to become lodged in enemy shields, forcing opponents to discard them. The pilum was a highly effective weapon that contributed significantly to Roman military success.

In the thousand years from the beginning of the Republic in 509 BC, to the collapse of the Western Roman Empire in 476 AD, the varied armies used a long list of Roman weapons for both attack and defence, all crucial to their military success and dominance. Swords and spears are the most famous, but there were others that were equally effective.

The Ballista

Developed from an earlier Greek weapon, the ballista, from the ancient Greek verb ballein, meaning ‘to throw’, was a crossbow-like siege weapon that used torsion springs to launch large bolts or heavy darts up to three hundred metres or more. It remained in use from the end of the Roman Republic – it was used by the armies of Julius Caesar in his first incursion into Britain in 55 BC – through to the late Empire.

The Onager

Again the result of development from Greek technology, the onager, named after a wild donkey for its powerful kicking action, was one of the later Roman Empire weapons, developed around the third century AD, or perhaps even earlier. It consisted of a large wooden frame with a single throwing arm and could launch heavy rocks or bowls of burning oil from a bucket or sling up to four hundred metres from a safe distance over walls, into enemy fortifications, or in open battlefield confrontations.

The Caltrop

The caltrop was an insidious anti-personnel and anti-cavalry weapon consisting of four sharp spikes arranged so that one spike always pointed upward. Caltrops were scattered on battlefields to impede cavalry and infantry movement by puncturing feet or hooves. So effective was the basic design, contemporary variants of these devices used to impede movement remain in use to this day, in the form of anti-tank defences and even stingers thrown across the width of a road by police to puncture the tyres of speeding cars.

This list of famous Roman weapons gives the briefest of glimpses into a millennia of warfare. The combination of brutally effective weaponry and unparalleled organisation allowed Rome, in all its richly fascinating and varied manifestations, to extend its reach and maintain control over vast and diverse territories, solidifying its legacy as one of history’s most powerful empires.