The Roman conquest of Iberia: logistics and supply difficulties

During the second century BC, Roman military commanders were faced with many challenges with regard to complex logistics when fighting wars in distant lands. These challenges related mainly to strategic logistics, particularly supplies from the metropolis. In the ancient world, shipment of supplies via the sea was quite risky. To ensure the proper provisioning of a particular place from Rome and its hinterland on schedule was not a trivial matter. An additional complicating factor were the conflicts of interests in Rome that often caused numerous delays in the shipment of supplies to the army in Hispania. At times, this resulted in smaller shipments than requested by the officers in the field. The direct result of this situation was the beginning of a methodical use of local resources for the subsistence of the Roman army.

One way by which the Romans tried to ease logistical problems was to have legionaries carry packs with provisions on their shoulders in order to avoid using too many pack animals. This practice probably started towards the end of the second century BC and ended with the reforms introduced by Gaius Marius. Despite all of the complex logistic problems that the Romans encountered in Hispania, the Roman logistic mechanisms were far more developed than those of the local peoples in the Peninsula. This provided the Romans an additional advantage in the battlefield, especially when recovering from military defeats.

Roman logistical superiority

Davies writes that the two main reasons for the supremacy of the Roman army were the skill of the soldiers and the quality of their equipment. To this we may add a third reason: the logistic capability of the Romans to send army forces across long distances by land and sea for long periods of time. This provided them a huge advantage when they set out to wage war. Among modern researchers, it is common to consider Rome primarily a land superpower, yet it was the first superpower to use ships for the purpose of systematically transporting supplies on a large scale (Roth 1998). This ability allowed Rome to fight not only in wars far from home, but to also conquer and control nearly any area in their vast empire; areas were later built up and developed. This is an ability that Hannibal lacked when invading the Apennine Peninsula.

The resources that were at the disposal of the Roman Republic were quite large in comparison to those of other peoples. Rome developed its resources and expanded them, using proper management and technological developments particularly in the realm of transport. The Romans built a network of roads and bridges on land, and fleets of merchant ships at sea that enabled them to use their resources at an unprecedented level of efficiency. Thus, Rome managed to build and manage a vast empire for hundreds of years using relatively small forces on a universal scale.

Types of military supplies

There were two types of military supplies: the supplies that the army carried in the field and the supplies that arrived from the home front. The Romans used two different terms to indicate the two types of supplies. The supplies that were transferred in a convoy along with the soldiers, the “initial supplies”, were called impedimenta. These were moved for example via supply train or convoy. At least 1,400 donkeys and hundreds of wagons accompanied each legion (Roth 1998). The second type of supplies, those arriving from the home front, was called commeatus (Roth 1998).

The impedimenta were an integral part of the army and followed it everywhere. As in other armies, this equipment was transported on wagons and pack animals, especially donkeys. It included the soldiers’ personal equipment and food. There were several differences between the Roman military transport network and that of other armies in ancient times: the fact that every soldier carried quite a heavy load, the uniformity of the equipment, and most important, the type of equipment that every legionary carried on his back.

The Roman legionary was probably the first soldier in history to carry, not only his personal equipment, but also additional equipment. In this he resembled the modern soldier more than the regular warrior in ancient times. Every eighth legionary (contubernium) received a donkey that carried the tent and accompanying equipment, something that recalls the transport of equipment carried by all-terrain vehicles in modern armies.

Raw materials

The Romans were capable of moving in the field with great speed together with all the impedimentathat they carried. Appian says that it took Julius Caesar only 27 days to reach Rome from Hispania; this despite the fact that his army was marching while carrying heavy equipment (App., Bell. civ. 2.15, 104). Even if the figure that Appian indicates seems somewhat low, it is still a remarkable achievement. We know that the Roman army had the means to renew the impedimenta. Each legion included professional artisans who were responsible for this task. Army camps contained ovens, pottery workshops, and workshops for the production and repair of weapons and other equipment. The soldiers cooked for themselves in their contubernium. This way, the legion and even the entire army could operate almost as a self-sufficient autarky. The only two missing elements were the raw materials, food and wood – for fuel and construction – in particular.

The raw materials arrived usually through the supply lines. This was one of the difficult problems that limited the army’s freedom of movement, especially an army that operated so far away from the home front. The greater the distance from the supply source, the greater the chances that something could go wrong along the way. In the case of Roman expansion into Hispania, this was exceptionally critical. As early as the beginning of the third century BC, Roman commanders in Hispania anticipated that it would be very hard for them to operate in the field while being completely dependent upon supplies arriving from home.

Appian considered the food consumed by the Roman army as the cause for deteriorating health of soldiers in Hispania. He claimed that their food did not contain all of the ingredients, – such as wine, oil, and salt – that he considered vital for the nutrition of the soldier (App. Hisp. 9.54). As early as 205 BC, prior to the establishment of the two provinces of Hispania, the Romans forced the locals to provide their army with clothing and “wheat for six months” (Liv. 29.3.5). Only several decades later, Roman governors of Hispania started collecting taxes officially and regularly. Around the beginning of the second century BC, the consul Cato claimed that the “war should feed itself”. He meant that the army should expropriate wheat and other essential provisions from the locals, instead of receiving these provisions from the home front (Liv. 34.9.12). It should also be noted that the supplies were delivered from Rome by private contractors (publicani or socii), mostly Italians, with quite dubious reputations (Liv. 23.48.4-12).

Like any other army, the operation and protection of the supply lines posed a problem for the Roman army. Though the Roman army was dependent upon the supply lines, it preferred, when possible, not to collect agricultural produce nor to cut down trees in the midst of a war (Roth 1998). The Romans would normally use marine supply lines (Polyb. 8.34.3, Liv. 26.39.19, 27.1–3), not surprising considering the presence of the Mediterranean Sea.

Obtaining and defending supplies

That the Romans recoiled from collecting food in hostile terrain is both logical and sensible; doing so involved taking great risks and having a high potential for contact with hostile elements. Still, very often they had no choice but to collect food. Warriors such as infantry soldiers or equestrians were sent to protect the ones collecting food (Erdkamp 2008, 103). But whenever possible, Roman generals preferred to purchase their provisions from the locals, thus significantly reducing danger to the soldiers. This is what the Romans did in the Celtiberian Wars of 195–194 BC. They would send groups of ten soldiers (deni) to fortified cities located on the tops of hills in order to purchase supplies in accordance with trade agreements forged between the Romans and Celtiberians (Liv. 34.19.8).

In the sources, there are different Latin terms, which refer to different types of provisions searched for and collection by the army (Sall. Iug. 93.2; Liv. 25.34.3, 31.36.5, 31.42.2, 33.7.9; Front. Strat.1.1.7, 2.13.6, 3.2.9,3.9.3; Tac. Ann. 1.35, 12.38). The main ones were: aquatio (the search for water), lignatio (the search for wood), abulatio (the search for hay for livestock), and frumentario(search for wheat and food for the people).

Groups of soldiers engaged in procuring supplies were naturally a tempting target for all types of raiders. The mountainous topography in most of the Hispanic areas enabled the ambush of small groups of soldiers. This happened to the Roman consul L. Lucullus, who attacked the Vaccei tribes without the approval of the Senate. The Senate “cut off” his lines of supply from Rome and in 153 BC he was forced to look for solutions to provide the needs of his army, as his resources dwindled quickly. The Vaccei warriors continuously attacked those sent to bring provisions to the army. Many Roman soldiers were killed during these missions, and in most cases, the soldiers returned empty handed (App. Hisp. 9.51). Lucullus’ need to continuously search for provisions in hostile areas weakened his position considerably.

During the siege of Numantia in 134–133 BC, Scipio Aemilianus provided his army with local produce collected by his soldiers in spite of the fact that he had a stable and certain supply line (App. Hisp.14.86). Livius says that Scipio Aemilianus forced each soldier to carry a 30-day supply of wheat (Liv. 26.8.9). Frontinus refers to the same issue, writing that Aemilianus’ soldiers carried with them supplies for several days (Front. Strat. 4.1.1). The shortage of water also became a severe problem for Aemilianus. According to Appian, the Roman army began to suffer from dehydration under the hot summer sun of the Hispanic meseta, and the soldiers were forced to dig and look for water wells. These wells provided small amounts of water of a poor quality. The men were saved but they paid a high price with the demise of their horses (App. Hisp. 14.88).

Gathering wood

One of the most important provisions was wood. The Roman army had many uses for wood, particularly in order to provide heat for soldiers during cold nights and also for the construction of legionary camps (or those of any other unit). The lumbermen suffered the greatest risks due to the long periods of time that they spent in one place. The local inhabitants, Celtiberians or Lusitanians, could easily ambush the Roman soldiers in the woods when they came to cut down trees. This occurred when Viriathus’ warriors attacked a unit that consul P. Maximus sent to cut down trees (App.Hisp.11.65). Apart from protection against enemy attacks, the Roman camp filled the important role of serving as a front logistic base.

The constant need to protect the supplies was a central factor in the alignment of the army during wars. The consul P. Maximus sent a number of legionaries to defend a group of lumbermen during his war against the Celtiberians (Plut. Mor. 8). Sometimes, the Romans took active protective measures against the enemy who would raid the patrols or supply convoys that were vital for an army operating so far away from home. This was Roman counter-guerilla warfare against hostile forces. One example is the ambush that Scipio Nassica, a pro-praetor of Hispania Ulterior in 193 BC, conducted against the enemy soldiers raiding his own troops. He surprised and defeated a group of Lusitanians who were returning to camp with the loot they had stolen Roman forces (App. Hisp. 11,61; Liv. 35.1.5).

In spite of the complicated supply issues experienced by the Romans in Spain, the Roman logistics machine was far better developed and more efficient than that of the indigenous peoples of Spain. The creation of new supply methods and the ability to quickly adapt to different challenges provided the Romans with an edge in battle, particularly when it came to regrouping in the wake of occasional defeats.

Daniel Varga is the Scientific Adviser of the Israel Antiquity Authority Southern District. His BA and MA studies focused on classical archaeology and history. In 2010, he completed his PhD thesis on guerrilla warfare during the conquest of the Iberian Peninsula by the Roman army (Ben-Gurion University).

Texts and translations

  • Appian, Appian’s Roman History: The Wars in Spain (translated by H. White, Harvard 1972).
  • Frontinus, The Stratagematon (edited by M.B. McElwain, London 1950).
  • Livius, Ab Urbe Condita (translated by Evan T. Stage, London 1935).
  • Plutarch, Moralia (translated by W. Heinemann, London 1927).
  • Polybius, The Histories (translated by W. Heinemann, London 1922).
  • Sallustius, Bellum Iugurthinum (translated by S.A. Handford, Middlesex 1963).
  • Tacitus, Annals (translated by J. Jackson, Harvard 1979).

Further reading

  • G. Davies, Service in the Roman Army (Edinburgh 1989).
  • P. Erdkamp, War and State Formation in the Roman Republic: A Companion to the Roman Army (Oxford 2008).
  • J.P. Roth, The Logistics of The Roman Army at War, 265 BC–AD 235 (Leiden 1998).

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