Roman pilum & plumbata

The army of the Roman Republic consisted of various types of warriors between the 4th and 2nd century BC. These Roman warriors all held citizenship and thus were part of the Roman warrior class. It was customary at this time for warriors to finance their own armor, which led to the emphasis on different ranks in the army based on wealth. The army consisted of various ranks: the Equites, the wealthiest class. These were cavalrymen. Velites, often these were young men and others with less wealth. The Hastati, they were armed with a pilum, scutum and sword. The Principes, they were armed the same as the Hastati but were wealthier and could afford body armor (the lorica hamata). The Triarii, these were the wealthiest and most experienced infantrymen and still fought according to the old phalanx formation with spear and shield. They also had a sword as a secondary weapon. 

The Verutum was a short javelin used in the Roman army. This javelin was used by the velites during ambushes and hit-and-run tactics on the battlefield. In contrast to the heavier pilum, which was used by the Hastati and Principes to weaken the enemy before engaging in hand-to-hand combat. The shafts of the verutum were about 1.1 meters long, significantly shorter than the 2-meter-long pilum. The tip was about 13 centimeters long. The verutum either had an iron shaft like the pilum or a tapered metal head. It was sometimes thrown using a throwing strap or amentum.

The verutum was likely adopted from the Samnites and the Volsci, but there is not enough evidence to confirm this. During the 3rd and 2nd century BC, the Roman light infantrymen (velites) carried seven veruta into battle. It proved to be a quite effective weapon, even against war elephants, as demonstrated in the Battle of Zama. At the end of the 2nd century BC, the verutum was phased out, along with the velites, but the javelin was reintroduced into the legionary equipment during the late empire.

The pilum was also developed during the Roman Republic. Later, it became the renowned javelin of the Roman legionaries.

It is not precisely known when Romans first started using the pilum. It is known that it was used before the 4th century BC, and according to one theory, the pilum was also adopted from the Samnites, Sabines, or Etruscans, who had similar javelins. In the armies of the Roman Republic, the pilum was used by the Hastati and Principes. An alternative theory is that the pilum, like the gladius, was adopted during the 1st Punic War from the Iberian mercenaries in the service of Carthage.

After the Social War (91 BC to 88 BC), the military structure changed and the Hastati and Principes became Roman legionaries. They continued to use the pilum. 

The pilum consisted of a long iron head with a small point at the front and a wooden shaft. There were different types of the pilum. The most common type had a flat tang at the bottom of the head, which was riveted into the widened top of the wooden shaft. A second type had a nested head, and a third, less known type, had a pointed tang. Throughout the long Roman history, the pilum underwent multiple changes and improvements.

The oldest form of the pilum had a leaf-shaped point and was originally used by the Etruscans. This model remained in use until the 2nd century AD. A late example of this type of pilum is part of the collection of the Archaeological Museum of München. This version of the pilum was probably lighter than the later versions that were developed. It is possible that this type of pilum was used less often by the legionaries than the later, heavier versions, although this cannot be said with certainty. This pilum was simply attached to a wooden shaft.

From the 2nd century BC, a new type of pilum was developed, featuring a head attached to the shaft with nails. The advantage of this version was that the head could be replaced while retaining the shaft. Additionally, the pila could be disassembled during marches, making them more convenient for the legionaries.

Later, the pilum underwent some minor changes, mostly in the way the point was attached to the shaft. The point was often serrated or pyramidal to increase penetration power.

In the 3rd-2nd century BC, the head of the pilum was usually shorter than later versions. The head was often 30-40 cm long and had a broad, flat point with barbs. The total weight of the pilum varied between 1 and 2.5 kg, depending on the specific model. The average length was about 2 meters, and the head was usually 60 cm long, although some specimens had a head of 90 cm. The head had a thickness of approximately 7 mm.

There were different ways to attach the head to the shaft. One method was the "socket" method, where a cavity at the end of the head was made to fit over the top of the shaft. Another commonly used method was attachment with a flat tang, which was fastened to the shaft with rivets. Originally, iron rivets were used, later also wooden rivets.

There is no archaeological evidence for the weighted pilum, but some visual sources, such as reliefs from the Palazzo della Cancelleria and metopes from the Tropaeum Traiani, depict a pilum with a spherical weight under the pyramid-shaped wooden part of the shaft. This type of pilum is dated between the Flavian period and Trajan's campaigns in Dacia (late 1st – early 2nd century AD).

What was the purpose of this ball? We are not sure, as no archaeological specimens have been found. The most logical explanation is that the ball was a weight, possibly made of lead or bronze. This could increase the impact force and penetrability of the weapon. This type of pilum would be an interesting choice for reenactment of a legionary from the late 1st or early 2nd century AD.

The bottom of the shaft often had an iron point that allowed the pilum to be stuck into the ground when needed. It is assumed that each legionary carried two pila, which had different weights. By the end of the Roman Empire, the pilum disappeared from the legionary's arsenal and was replaced by the plumbata.

The pilum was just as important to a Roman legionary as the gladius or the scutum. This particular spear was as powerful as the swords of the legionaries and the spears of the auxiliary troops. Every legionary always carried one or more pila on his shoulder, in addition to his furca (a cross-shaped carrying device for personal belongings).

During the Republic, each legionary carried two pila: one light and one heavy. However, images of imperial legionaries often show only one pilum, although some also depict two pila that were identical and had the same function. It seems that legionaries still carried two pila, but without the distinction between a "light" and a "heavy" version.

A well-known theory is that the iron tip of the pilum was supposed to bend when it hit its target. This way, the enemy could not throw the javelins back at the Romans. However, experimental archaeology has shown that the tips of the pilum barely bent after being used. The fact that these spears hit their mark in enemy shields was already enough to make the enemy throw away his shield, thereby making him vulnerable to the Roman charge that occurred a few seconds later. The tip of the pilum can be easily removed from the shaft. This possibly had a practical purpose so that tips could be quickly replaced and the expensive shaft could be reused.

The special shape of the pilum made it difficult to pull out of the shield, and the long iron shaft made it nearly impossible to cut off. This forced the enemy to discard his shield, making him vulnerable to hand-to-hand combat with the legionnaires. However, some sources, such as Matt Amt of Legio XX, note that the ability to remove a shield was often exaggerated – after all, the pilum was designed to kill.

The pilum was primarily a javelin, designed to strike the enemy at relatively short range. In actual battles, legionaries threw the pilum up to 35 meters, aiming to confuse the enemy. A direct hit with the pilum's point was particularly dangerous, as the heavy versions could penetrate armor and cause severe injuries.

In his Commentaries on the Gallic War, Caesar described the effect of a volley of pila on the enemy: 'The soldiers threw their heavy spears from above and easily broke through the enemy's formation'.

Additionally, the pilum could also be used for thrusting, for example against cavalry attacks. This was particularly useful in the Battle of Pharsalus (48 BC) when Caesar deployed his troops against Pompey's cavalry: "Caesar gave the signal and his cavalry made way, after which three thousand soldiers from the reserve came forward. They pointed their spears upward at the cavalry. The cavalry, unaccustomed to such fights, could not withstand the blows and fled." With the butt cap at the back, the pilum could be fixed in the ground like the Greek dory. 

As a successor to the pilum, another type javelin developed in the form of a large dart. Plumbatae or martiobarbuli were lead-weighted throwing darts carried by Late Roman infantrymen. They had the same function as the pilum but were significantly shorter and more unpredictable. Roman soldiers in some legions carried plumbatae. These were attached in leather rings at the back of the shield.  This allowed them to be used unexpectedly. Their design allowed them to be thrown over a longer distance than the earlier pilum.

The plumbata consisted of a lead-weighted head attached to a wooden shaft with fletching, allowing soldiers to effectively throw them over long distances. The Roman work De rebus bellicis and the Byzantine war manual Strategicon confirm the use of plumbatae and describe variations, such as the barbed plumbatae (plumbata tribolata). Archaeological finds in Wroxeter and elsewhere confirm the descriptions and the use of these weapons.

The complete weapon consisted of a head, shaft, and fletching at the back.  The earliest examples seem to have been carried by the ancient Greeks from around 500 BC, but the most renowned users were the late Roman and Eastern Roman armies. The earliest and best-documented source for these weapons refers to a period around 300 AD, although the document was compiled around 390–450 AD.

Vegetius mentions in his 4th-century Re militari, 1.17:

"The exercise of the loaded javelins, called martiobarbuli, must not be omitted. In the past, we had two legions in Illyria, each consisting of six thousand men, who, through their extraordinary dexterity and skill in using these weapons, bore the same name. They supported the weight of all wars for a long time and distinguished themselves so remarkably that the emperors Diocletian and Maximian honored them with the titles Jovianus and Herculean upon their accession and chose them above all other legions. Each soldier carries five of these javelins in the hollow of his shield. Thus, the legionaries seem to take the place of archers, as they injure both the men and the horses of the enemy before coming within range of the ordinary throwing weapons."

A second source, also from the late 4th century, titled De rebus bellicis shows what these weapons looked like. The illustration depicts what appears to be a short arrow with a weight attached to the shaft. Although only later copies of the original manuscript exist, this is confirmed by the remains found so far in the archaeological excavations.

Plumbatae etymologically contains plumbum, meaning lead, and can be translated as "lead-weight [throwing stones]". Martiobarbuli in this translation is mattiobarbuli in Latin, which is likely an assimilation of Martio-barbuli, or "little barbs of Mars". The "barb" implies a barbed head.