Structural history of the Roman military
The structural history of the Roman military concerns the major transformations in the organization and constitution of ancient Rome's armed forces, "the most effective and long-lived military institution known to history." From its origins around 800 BC to its final dissolution in AD 476 with the demise of the Western Roman Empire, Rome's military organization underwent substantial structural change. At the highest level of structure, the forces were split into the Roman army and the Roman navy, although these two branches were less distinct than in many modern national defense forces. Within the top levels of both army and navy, structural changes occurred as a result of both positive military reform and organic structural evolution; these changes can be divided into four distinct phases. Phase I The army was derived from obligatory annual military service levied on the citizenry, as part of their duty to the state. During this period, the Roman army would wage seasonal campaigns against local adversaries.
Phase II As the extent of the territories falling under Roman control expanded and the size of the forces increased, the soldiery became salaried professionals. As a consequence, military service at the lower levels became progressively longer-term. Roman military units of the period were homogeneous and regulated; the army consisted of units of citizen infantry known as legions as well as non-legionary allied troops known as auxilia. The latter were most called upon to provide light infantry, logistical, or cavalry support. Phase III At the height of the Roman Empire's power, forces were tasked with manning and securing the borders of the vast provinces, brought under Roman control. Serious strategic threats were less common in this period and emphasis was placed on preserving gained territory; the army underwent changes in response to these new needs and became more dependent on fixed garrisons than on march-camps and continuous field operations. Phase IV As Rome began to struggle to keep control over its sprawling territories, military service continued to be salaried and professional for Rome's regular troops.
However, the trend of employing allied or mercenary elements was expanded to such an extent that these troops came to represent a substantial proportion of the armed forces. At the same time, the uniformity of structure found in Rome's earlier military disappeared. Soldiery of the era ranged from armed mounted archers to heavy infantry, in regiments of varying size and quality; this was accompanied by a trend in the late empire of an increasing predominance of cavalry rather than infantry troops, as well as a requirement for more mobile operations. In this period there was more focus on smaller units of independently-operating troops, engaging less in set-piece battles and more in low-intensity, guerilla actions. According to the historians Livy and Dionysius of Halicarnassus, writing at a far date, the earliest Roman army existed in the 8th century BC. During this period Rome itself was little more than a fortified hilltop settlement and its army a small force, whose activities were limited "mainly raiding and cattle rustling with the occasional skirmish-like battle".
Historian Theodor Mommsen referred to it as Rome's curiate army, named for its presumed subdivision along the boundaries of Rome's three founding tribes, the Ramnians and Luceres. This army's exact structure is not known, but it is probable that it loosely resembled a warrior band or group of bodyguards led by a chieftain or king. Mommsen believes that Roman military organization of this period was regimented by the "Laws of King Italus" but these laws, though referred to by Aristotle, have been lost; the army consisted, according to Livy, of 3,000 infantry and 300 horsemen, one third from each of Rome's three founding tribes. Warriors served under six "leaders of division" who in turn served under a general in the person of the reigning King. Mommsen uses philological arguments and references from Livy and others to suggest that the greater mass of foot-soldiers consisted of pilumni, with a smaller number serving as arquites; the cavalry was far smaller in number and consisted of the town's richest citizens.
The army may have contained the earliest form of chariots, hinted at by references to the flexuntes. By the beginning of the 7th century BC, the Iron-Age Etruscan civilization was dominant in the region. Like most of the other peoples in the region, the Romans warred against the Etruscans. By the close of the century, the Romans had lost their struggle for independence, the Etruscans had conquered Rome, establishing a military dictatorship, or kingdom, in the city. Although several Roman sources including Livy and Polybius talk extensively about the Roman army of the Roman Kingdom period that followed the Etruscan capture of the city, no contemporary accounts survive. Polybius, for example, was writing some 300 years after the events in question, Livy some 500 years later. Additionally, what records were kept by the Romans at this time were destroyed when the city was sacked; the sources for this period cannot therefore be seen as reliable, as they can be for military history, e.g. from the First Punic War onwards.
According to our surviving narratives, the three kings of Rome during the Etruscan occupation were Tarquinius Priscus, Servius Tullius, Tarquinius Superbus. During this period the army underwent a reformation into a centurial army based on socio-economic class; this reformation is traditionally attributed to Servius Tullius
Founding of Rome
The tale of the Founding of Rome is recounted in traditional stories handed down by the ancient Romans themselves as the earliest history of their city in terms of legend and myth. The most familiar of these myths, the most famous of all Roman myths, is the story of Romulus and Remus, twins who were suckled by a she-wolf as infants in the 8th century BC. Another account, set earlier in time, claims that the Roman people are descended from Trojan War hero Aeneas, who escaped to Italy after the war, whose son, was the ancestor of the family of Julius Caesar; the archaeological evidence of human occupation of the area of modern-day Rome, Italy dates from about 14,000 years ago. The national epic of mythical Rome, the Aeneid of Virgil, tells the story of how Trojan prince Aeneas came to Italy; the Aeneid was written under Augustus, who claimed ancestry through Julius Caesar and his mother Venus. According to the Aeneid, the survivors from the fallen city of Troy banded together under Aeneas and underwent a series of adventures around the Mediterranean Sea, including a stop at newly founded Carthage under the rule of Queen Dido reaching the Italian coast.
The Trojans were thought to have landed in an area between modern Anzio and Fiumicino, southwest of Rome at Laurentum or, in other versions, at Lavinium, a place named for Lavinia, the daughter of King Latinus whom Aeneas married. This started a series of armed conflicts with Turnus over the marriage of Lavinia. Before the arrival of Aeneas, Turnus was betrothed to Lavinia, who married Aeneas, starting the war. Aeneas killed Turnus; the Trojans won the right to assimilate with the local peoples. The young son of Aeneas, Ascanius known as Iulus, went on to found Alba Longa and the line of Alban kings who filled the chronological gap between the Trojan saga and the traditional founding of Rome in the 8th century BC. Toward the end of this line, King Procas was the father of Amulius. At Procas' death, Numitor became king of Alba Longa, but Amulius captured him and sent him to prison. Forests have a prominent role in the founding myth-when Aeneas arrives at the site that would become Rome it is still forest: Evander goes on to explain that from that "first time" the god Saturn brings these scattered people laws and bestows upon them the name Latium.
The myth of Aeneas was of Greek origin and had to be reconciled with the Italian myth of Romulus and Remus, who would have been born around 771 BC if taken as historical figures. They were purported to be sons of Rhea Silvia and either Mars, the god of war, or the demi-god hero Hercules, they were abandoned at birth, in the manner of many mythological heroes, because of a prophecy that they would overthrow their great-uncle Amulius, who had overthrown Silvia's father Numitor. The twins were abandoned on the river Tiber by servants who took pity on the infants, despite their orders; the twins were nurtured by a she-wolf until a shepherd named Faustulus found the boys and took them as his sons. Faustulus and his wife Acca Larentia raised the children; when Remus and Romulus became adults, they killed restored Numitor. They decided to establish a city. Thus, Rome began with a fratricide, a story, taken to represent the city's history of internecine political strife and bloodshed. Strabo writes that there is an older story, about the founding of Rome, than the previous legends that he had mentioned.
The city was founded by Evander. Strabo writes that Lucius Coelius Antipater believed that Rome was founded by Greeks. Dionysius of Halicarnassus writes that the people who came to the lands that became the city of Rome were first, the Aborigines, who drove the Sicels out of these lands, were from the Arcadia the Pelasgians, who came from Thessaly, third those who came into Italy with Evander from the city of Pallantium in Arcadia, after them the Epeans from Elis and Pheneats from Pheneus, who were part of the army commanded by Heracles who decided to stay there while they were returning from the expedition at the Erytheia, with whom a Trojan element was commingled and last of all, the Trojans who had escaped with Aeneas from Ilium and the other Trojan cities. Dionysius mentions that the Trojans, were Greek people who were from the Peloponnesus, he adds that Romans say that the Pallantium was founded by Greeks from Pallantium of Arcadia, about sixty years before the Trojan war and the leader was Evander.
At the sixteenth generation after the Trojan war the Albans united these places into one settlement, surrounding them with a wall and a ditch. The Albans were a mixed nation composed of all the above people. Dionysius adds that it is that a barbarian element from among the neighboring people or a remnant of the ancient inhabitants of the place were mixed with the Greek, but all these people, having lost their national identity came to be called by one common name, after Latinus, the king of the country. The leaders of the colony were the twin brothers Remus. Another story told how a son of Odysseus and Circe, was the one who founded Rome. Martin P. Nilsson speculates that this older story was becoming a bit embarrassing as Rome became more powerful and tensions with the Greeks grew. Being descendants of the Greeks was no longer preferable, so the Romans settled on the Trojan foundation myth instead. Nilsson further speculates that the name of Romos was changed by the Romans to the native name Romulus, but the name Romos was never forgotten by the people
The Wetterau Limes is the name given in the field of historical research to that part of the Upper Germanic-Rhaetian Limes which enclosed the region that became known as the Wetterau in the German state of Hesse. During the two campaigns of the Roman Emperor Domitian against the Chatti, the Romans began to cut swathes of open ground through the dense forests of today's Hesse, in order to prevent their columns from being ambushed. On the crest of the Taunus mountain range, such a swathe served as a surveillance route. After the end of the Chatti Wars, the Romans began to secure these conquered regions east of the Rhine with a limes - a line of forts, fortlets and palisades; the forest road was guarded by wooden watchtowers to ensure continuous observation. This ensured that the southern slopes of the Taunus mountains and the fertile and strategically important Wetterau became part of the Roman Empire. In addition to the establishment of this frontier, Domitian turned the two Germanic military territories of Upper and Lower Germanian into Roman provinces.
In spite of this rather modest conquest, he was subsequently celebrated in Rome with great pomp as a triumphator and coins were minted with the ambitious claim Germania capta. The propaganda nature of this policy is evinced by the fact that in the narrow province of Upper Germania there were hardly any Germanii, the area was populated entirely by Celts; the long-held conviction that the Neckar-Odenwald Limes was erected at the same time as the Wetterau Limes after the Chatti wars, is now regarded as having been rejected. Although there were Roman military outposts on the eastern side of the Rhine from the seventies, the border running along the Odenwald-Neckar Line to Donnstetten is now dated by most sources as having not been erected before 98 AD; the state of preservation of the limes is poor due to the heavy agricultural use of the Wetterau. Only a few sections on the foothills of the Taunus, at Echzell and east of Hanau are visible above ground. In the early days of limes research, this situation meant that the eastern Wetterau section remained undiscovered.
This was not disproved until the 1880s by excavations of the Hanauer Geschichtsverein under Albert Duncker and Georg Wolff. Like the other sections of the Upper German-Raetian Limes, the Wetterau Limes was reinforced and expanded. In the eastern Wetterau the dates when the individual forts were first built are not uniform, it is clear that there was a defensive line from Oberflorstadt via Heldenbergen and Hanau-Mittelbuchen to Hanau-Salisberg The forts on the line further east from Marköbel via Rückingen to Großkrotzenburg were not built until the time of Trajan. The neighbouring Taunus line was reinforced in the second half of the second century by the numerus forts of Holzhausen, Kleiner Feldberg and Kapersburg; the further expansion of the limes defences to the north of the Wetterau was in order to protect its fertile soils on the one hand and to meet the high demand for the supply of the troops stationed on the limes and legion camps in Mainz. Archaeobotanical studies have calculated that an annual requirement of 3,034 tons of grain and 10,371 tons of hay were required to supply for the north-facing bulge of the limes in the Wetterau.
The end of the Wetterau Limes came in the year 259-260 AD, when Rome abandoned all areas to the east of the Rhine. Thus, for example, the pottery trade, once flourishing in the Wetterau came to a standstill. Imports of pottery from the Rhineland dominate archaeological collections from the second third of the 3rd century. Bricks found in the area do not seem to have been fired as they used to be. More and more older building material was used instead. Hypocaust heating was replaced by much simpler heating pipe systems. From the border area, there are other interesting finds which shed further light on the period of the limes; this includes the treasure of Ober-Florstadt, concealed during the course of Germanic invasions in AD 233. In 1603, the inscription of a collegium iuventutis was discovered in the area around Altenstadt Roman Fort; this may have been a unit set up to act as a local militia. Kapersburg Roman Fort was reduced during its last days. There is evidence of a local unit, a numberus nidensium, raised in the civitas capital of Nida-Heddernheim.
Lochmühle Fortlet Kapersburg Roman Fort Ockstädter Wald Fortlet Kaisergrube Fortlet Am Eichkopf Fortlet Langenhain Roman Fort Hunnenkirchhof Fortlet Butzbach Roman Fort Degerfeld Fortlet Dicker Wald Fortlet Holzheimer Unterwald Fortlet Hainhaus Fortlet Arnsburg Roman Fort Langsdorf Fortlet Feldheimer Wald Fortlet Inheiden Roman Fort Auf dem Wingertsberg Fortlet Massohl Fortlet Auf der Burg Fortlet Haselheck Fortlet Echzell Roman Fort Lochberg Fortlet Staden Fortlet Ober-Florstadt Roman Fort Stammheim Fortlet Altenstadt Roman Fort Auf dem Buchkopf Fortlet Marköbel Roman Fort Langendiebach Fortlet Rückingen Roman Fort Neuwirtshaus Fortlet Großkrotzenburg Roman Fort The following museums have a permanent exhibition on the Wetterau Limes or individual sites along it: Saalburg Museum, Bad Homburg Wetterau Museum, Friedberg Butzbach Municipal Museum Limes Information Centre at Hof Graß Echzell Local History Museum Heuson Museum, Büdingen Erlensee-Rückingen Local History Museum Schloss Steinheim Museum Großkrotzenburg Museum Limes Dietwulf Baatz and Fritz-Rudolf
Campaign history of the Roman military
From its origin as a city-state on the peninsula of Italy in the 8th century BC, to its rise as an empire covering much of Southern Europe, Western Europe, the Middle East and North Africa to its fall in the 5th century AD, the political history of Ancient Rome was entwined with its military history. The core of the campaign history of the Roman military is an aggregate of different accounts of the Roman military's land battles, from its initial defense against and subsequent conquest of the city's hilltop neighbors on the Italian peninsula, to the ultimate struggle of the Western Roman Empire for its existence against invading Huns and Germanic tribes; these accounts were written by various authors after the history of the Empire. Following the First Punic War, naval battles were less significant than land battles to the military history of Rome due to its encompassment of lands of the periphery and its unchallenged dominance of the Mediterranean Sea; the Roman army battled first against its tribal neighbours and Etruscan towns within Italy, came to dominate the Mediterranean and at its height the provinces of Britannia and Asia Minor.
As with most ancient civilizations, Rome's military served the triple purpose of securing its borders, exploiting peripheral areas through measures such as imposing tribute on conquered peoples, maintaining internal order. From the outset, Rome's military typified this pattern, the majority of Rome's campaigns were characterised by one of two types; the first is the territorial expansionist campaign begun as a counter-offensive, in which each victory brought subjugation of large areas of territory and allowed Rome to grow from a small town to a population of 55 million in the early empire when expansion was halted. The second is the civil war. Roman armies were not invincible, despite their formidable reputation and host of victories, Romans "produced their share of incompetents" who led Roman armies into catastrophic defeats, it was the fate of the greatest of Rome's enemies, such as Pyrrhus and Hannibal, to win the battle but lose the war. The history of Rome's campaigning is, if nothing else, a history of obstinate persistence overcoming appalling losses.
Knowledge of Roman history stands apart from other civilizations in the ancient world. Its chronicles and otherwise, document the city's foundation to its eventual demise. Although some histories have been lost, such as Trajan's account of the Dacian Wars, others, such as Rome's earliest histories, are at least semi-apocryphal, the extant histories of Rome's military history are extensive. Rome's earliest history, from the time of its founding as a small tribal village, to the downfall of its kings, is the least well preserved. Although the early Romans were literate to some degree, this void may be due to the lack of will to record their history at that time, or such histories as they did record were lost. Although the Roman historian Livy lists a series of seven kings of early Rome in his work Ab urbe condita, from its establishment through its earliest years, the first four kings may be apocryphal. A number of points of view have been proposed. Grant and others argue that prior to the establishment of the Etruscan kingdom of Rome under the traditional fifth king, Tarquinius Priscus, Rome would have been led by a religious leader of some sort.
Little is known of Rome's military history from this era, what history has come down to us is more of a legendary than of factual nature. Traditionally, after founding the city, fortified the Palatine Hill, shortly thereafter, Rome was "equal to any of the surrounding cities in her prowess in war"; the first of the campaigns fought by the Romans in this legendary account are the wars with various Latin cities and the Sabines. According to Livy, the Latin village of Caenina responded to the event of the abduction of the Sabine women by invading Roman territory, but were routed and their village captured; the Latins of Antemnae and those of Crustumerium were defeated next in a similar fashion. The remaining main body of the Sabines attacked Rome and captured the citadel, but were convinced to conclude a treaty with the Romans under which the Sabines became Roman citizens. There was a further war in the 8th century BC against Veii. In the 7th century BC there was a war with Alba Longa, a second war with Fidenae and Veii and a second Sabine War.
Ancus Marcius led Rome to victory against the Latins and, according to the Fasti Triumphales, over the Veientes and Sabines also. Lucius Tarquinius Priscus' first war was waged against the Latins. Tarquinius took great booty from there back to Rome. According to the Fasti Triumphales, the war occurred prior to 588 BC, his military ability was tested by an attack from the Sabines. Tarquinius doubled the numbers of equites to help the war effort, defeat the Sabines. In the peace negotiations that followed, Tarquinius received the town of Collatia and appointed his nephew, Arruns Tarquinius known as Egerius, as commander of the garrison which he stationed in that city. Tarquinius returned to Rome and celebrated a triumph for his victories that, according to the Fasti Triumphales, occurred on 13 September 585 BC. Subsequently, the Latin cities of Corniculum, old Ficulea, Crustumerium, Ameriola and Nomentum were subdued and became Roman. Early in his reign, Servius Tullius warred against Veii and the Etruscans.
He is said to have shown valour in the campaign, to have routed a great army of the enemy. The war helped him to cement his position at Rome. According to t
Velites were a class of infantry in the Roman army of the mid-Republic from 211 to 107 BC. Velites were light infantry and skirmishers who were armed with a number of darts, each with a 30-inch wooden shaft the diameter of a finger, with a c. 10-inch narrow metal point, to fling at the enemy. They carried short thrusting swords, or gladii, for use in melee, they wore armour as they were the youngest and poorest soldiers in the legion and could not afford much equipment. They did carry small wooden shields called parma for protection, wore headdresses made from wolf skins so their brave deeds could be recognized; the velites were placed at the front for tactical reasons, so that they had the opportunity to secure glory for themselves in single combat. Velites did not form their own units, they were used as a screening force, driving off enemy skirmishers and disrupting enemy formations with javelin throws before retiring behind the lines to allow the heavier-armed hastati to attack. They were the ones who engaged war elephants and chariots if they were present on the field, such as in the Battle of Zama, in 202 BC.
Their high mobility and ranged weaponry made them much more effective against these enemies than heavy infantry. An early Roman legion contained 1,000 velites. Velites were disbanded after the Marian reforms. Lucilius suggests that rorarii and velites were interchangeable, with velites superseding rorarii. Another theory is that the leves' equipment was upgraded until they were at the same level as the rorarii, they both collectively became known as the velites. Velites were the youngest and the poorest soldiers in the legion, could afford much equipment, they were armed with veretum, light javelins, each with a 90 cm wooden shaft the diameter of a finger, with a c. 10-inch narrow metal point, tips designed to bend on impact to prevent them being thrown back, similar to the heavier pila of other legionaries. Livy says that they each carried seven javelins, however Roman satirist Lucilius says that they carried five, suggesting that the amount may have changed, they carried darts, 30 inches long, which had a tip, designed to bend on impact.
The hastati and principes carried gladii short thrusting swords 74 centimetres in length, as their main weapons, the velites carried them as backup weapons. They fought in a loose, staggered formation like most irregular troops, carried small round shields called parma, 90 cm in diameter; the velites were placed at the front of the maniples, so that the velites had the chance to prove themselves and win glory by seeking out single combat with an enemy. This is why they wore identifiable wolfskin headdresses. "These are not given to a soldier if in the formed array... but to those who in the skirmishing or in similar circumstances in which there is no need to engage in single combat, have voluntarily and by choice placed themselves in danger." In the legion, the velites were attached to each maniple of hastati and triarii. They formed up at the front of the legion before battle to harass the enemy with javelin throws and to prevent the enemy doing the same before retiring behind the lines to allow the heavier infantry to attack.
After they had fallen back, they would move up behind the attacking troops and throw darts at the enemy. They sometimes carried wounded back to the rear, however a corps of deportates did this. In a pitched battle, the velites would form up at the front of the legion and cover the advance of the hastati, who were armed with swords. If the hastati failed to break the enemy, they would fall back and let the principes equipped though more experienced infantry, take over. If the principes failed, they would retire behind the triarii, well trained armoured, spear armed legionaries and let them attack; the number of triarii was fixed at 600 per legion, there were 1,200 hastati and 1,200 principes per legion, with the rest being light infantry like the velites. In the standard legion around the time of the Second Punic War there were 10 maniples of hastati, each having 120 hastati, with 40 velites attached; the maniples were further split into centuries, of 60 hastati and 20 velites, with the centurion of the hastati century commanding the velites as well.
After the Romans were ambushed at the Battle of Lake Trasimene, which remains the largest ambush in military history by men involved, in 217 BC, Quintus Fabius Maximus Verrucosus introduced a military step known as the agmen. It was a variable formation, with one or more columns, separated by cohorts, with their allies in between the cohorts; the front of the columns were the extraordinarii, along with some of the velites. Following this formation was a rear-guard of the ablecti, the rest of the velites; the baggage trail was guarded by the cavalry. Both the front and the flanks contained a number of speculatores, to provide warning of an enemy army's approach; when enemies were nearby, the baggage train would be dispersed between the maniples. If the columns were forced to retreat, the velites and the extraordinarii that were in the front guarded the retreat of the others; when the Romans set up a temporary castra, two maniples were selected to pitch the tents of the headquarters and officers, details were made for fatigue duty
Military of ancient Rome
The military of ancient Rome, according to Titus Livius, one of the more illustrious historians of Rome over the centuries, was a key element in the rise of Rome over “above seven hundred years” from a small settlement in Latium to the capital of an empire governing a wide region around the shores of the Mediterranean, or, as the Romans themselves said, ‘’mare nostrum’’, “our sea.” Livy asserts ”... if any people ought to be allowed to consecrate their origins and refer them to a divine source, so great is the military glory of the Roman People that when they profess that their Father and the Father of their Founder was none other than Mars, the nations of the earth may well submit to this with as good a grace as they submit to Rome's dominion.”Titus Flavius Josephus, a contemporary historian, sometime high-ranking officer in the Roman army, commander of the rebels in the Jewish revolt, describes the Roman people as if they were "born ready armed." At the time of the two historians, Roman society had evolved an effective military and had used it to defend itself against the Etruscans, the Italics, the Greeks, the Gauls, the maritime empire of Carthage, the Macedonian kingdoms.
In each war it acquired more territory until, when civil war ended the Roman Republic, nothing was left for the first emperor, Augustus, to do except declare it an empire and defend it. The role and structure of the military was altered during the empire, it became less Roman, the duties of border protection and territorial administration being more and more taken by foreign mercenaries officered by Romans. When they divided at last into warring factions the empire fell." ’’ - an agency designated by'SPQR' on public inscriptions. Its main body was the senate, its decrees were handed off to the two chief officers of the consuls. They could levy from the citizens whatever military force they judged was necessary to execute such decree; this conscription was executed through a draft of male citizens assembled by age class. The officers of the legion were tasked with selecting men for the ranks; the will of the SPQR was binding on the consuls and the men, with the death penalty assigned for disobedience or failure.
The men were under a rigorous code, known now for its punitive crucifixion. The consular duties were of any type whatever: military defense, police work, public hygiene, assistance in civil disaster, health work and construction of public roads, aqueducts and the maintenance of such; the soldiers were kept busy doing whatever service needed to be done: soldiering, manning vessels, blacksmithing, etc. They were trained as required, but previous skills, such as a trade, were exploited, they were protected by the authority of the state. The military's campaign history stretched over 1300 years and saw Roman armies campaigning as far east as Parthia, as far south as Africa and Aegyptus and as far north as Britannia; the makeup of the Roman military changed over its history, from its early history as an unsalaried citizen militia to a professional force, the Imperial Roman army. The equipment used by the military altered in type over time, though there were few technological improvements in weapons manufacture, in common with the rest of the classical world.
For much of its history, the vast majority of Rome's forces were maintained at or beyond the limits of its territory, in order to either expand Rome's domain, or protect its existing borders. Expansions were infrequent, as the emperors, adopting a strategy of fixed lines of defense, had determined to maintain existing borders. For that purpose they created permanent stations that became cities. At its territorial height, the Roman Empire may have contained between 45 million and 120 million people. Historian Edward Gibbon estimated that the size of the Roman army "most formed a standing force of three hundred and seventy-five thousand men" at the Empire's territorial peak in the time of the Roman Emperor Hadrian; this estimate included only legionary and auxiliary troops of the Roman army. However, Gibbon states that it is "not... easy to define the size of the Roman military with any tolerable accuracy." In the late Imperial period, when vast numbers of foederati were employed by the Romans, Antonio Santosuosso estimated the combined number of men in arms of the two Roman empires numbered closer to 700,000 in total, drawing on data from the Notitia Dignitatum.
However, he notes that these figures were subject to inflation due to the practice of leaving dead soldiers "on the books" in order to continue to draw their wage and ration. Furthermore, it is irrespective of whether the troops were raised by the Romans or hired by them to fight on their behalf. Rome's military consisted of an annual citizen levy performing military service as part of their duty to the state. During this period, the Roman army would prosecute seasonal campaigns against local adversaries; as the extent of the territories falling under Roman suzerainty expanded, the size of the city's forces increased, the soldiery of ancient Rome became professional and salaried. As a consequence, military service at the lower levels became progressively longer-term. Roman military units of the period were homogeneous and regulated; the army consisted of units of citizen infantry known as legions as well as non-legionary allied troops known
Roman siege engines
Roman siege engines were, for the most part, adapted from Hellenistic siege technology. Small efforts were made to develop the technology. Up to the first century BC, the Romans utilized siege weapons only as required and relied for the most part on ladders and rams to assault a fortified town. Ballistae were employed, but held no permanent place within a legion's roster, until in the republic, were used sparingly. Julius Caesar took great interest in the integration of advanced siege engines, organizing their use for optimal battlefield efficiency. To facilitate this organization and the army’s self-sufficiency, an engineering corps was developed. An officer of engineers, or praefectus fabrum, is referenced in armies of the late republic, but this post is not verifiable in all accounts and may have been a military advisor on the personal staff of a commanding officer. There were legion architects who were responsible for the construction of war machines who would assure that all artillery constructions in the field were level.
Ensuring that constructions were level was the job of the libratores, who would launch missiles and other projectiles during battle. The engineering corps was in charge of massive production prefabricating artillery and siege equipment to facilitate its transportation. Roman artillery was efficient at that time, during a siege the Romans would attack the weakest area of their enemy's defenses and attempt to breach the walls at that point. To support this effort, artillery fire would commence, with three main objectives: to cause damage to defenses, casualties among the opposing army, loss of enemy morale, it would provide cover fire for troops building siege ramps or those in siege towers. There were machines called tormenta, which would launch projectiles such as javelins, rocks, or beams; these devices were on wheeled platforms to follow the line’s advance. All were "predicated on a principle of physics: a lever was inserted into a skein of twisted horsehair to increase torsion, when the arm was released, a considerable amount of energy was thus freed".
It was stated that sinew, instead of twisted hair, provided a better “spring.” These weapons were high-maintenance devices and vulnerable to having their leather, sinew, or hemp skeins affected by wet or damp, which would cause them to slacken and lose tension, rendering the engine useless. It is somewhat difficult to define and describe Roman artillery, as names are confused and historians still do not agree on all definitions. Best known are the ballista, the onager, the scorpio. After the absorption of the ancient Greek city states into the Roman Republic in 146 BC, some advanced Greek technologies began to spread across many areas of Roman influence; this included the hugely advantageous military advances the Greeks had made, as well as all the scientific, mathematical and artistic developments. The Romans'inherited' the torsion powered ballistae which had by now spread to several cities around the Mediterranean, all of which became Roman spoils of war in time, including one from Pergamum, depicted among a pile of'trophy' weapons in relief on a balustrade.
The torsion ballista, developed by Alexander, was a far more complicated weapon than its predecessor, the Romans developed it further. Vitruvius, in his De Architectura book X, describes the tuning of ballistae; every century in the Roman army had a ballista by the 1st century AD. It was the command of the chief of the ballistae, under whom were the artillery experts, or doctores ballistarum and the artillerymen, or ballistarii. Ballistae were heavy missile weapons, they resembled large crossbows, rather than catapults. They were powered by two horizontal like arms, which were inserted into two vertical and wound "skein" springs contained in a rectangular frame structure making up the head or principal part of the weapon; the arms were drawn rearward with a winch lever to further twist the skeins and thus gain the torsion power to cast a projectile. It has been said that the whirring sound of a ballista-fired stone struck fear and dread into the hearts of those inside the walls of besieged cities.
The stones chosen to be used in the ballista had to be a particular sort. According to Vegetius, river stones were best, since they are round and dense. Ballista stones found at the site of Masada were chiseled to make them as round as possible; the early Roman ballistae were made of wood, held together with iron plates around the frames and iron nails in the stand. The main stand had a slider on the top, into which were loaded the bolts or stone'shot'. Attached to this, at the back, was a pair of winches and a claw, used to ratchet the bowstring back to the armed firing position. A slider passed through the field frames of the weapon, in which were located the torsion springs, which were twisted around the bow arms, which in turn were attached to the bowstring. Drawing the bowstring back with the winches twisted the taut springs, storing the energy to fire the projectiles; the ballista was a accurate weapon, but some design aspects meant it could compromise its accuracy for range. The lightweight bolts could not gain the high momentum of the stones over the same distance as those th