Campaign history of the Roman military

Rome was a militarized state whose history was often closely entwined with its military history over the 1228 years that the Roman state is traditionally said to have existed. The core of Roman military history is the account of its great land battles, from the conquest of Italy to its final battles against the Huns. This account may be divided into the Republic period, when Rome was primarily expansionist, and the Imperial period, when Rome focused on maintaining its borders.

Institutions

Roman army

History and evolution

'The Roman Army' is the name given to the sophisticated collection of soldiers and other military forces which served the Roman Republic and later the Roman Empire. The Army dominated much of the land surrounding the Mediterranean Sea, including the province of Britain and Asia Minor at the Empire's height. Beginning as a citizen army, the Roman Army evolved into a professional army following the reforms of Gaius Marius around 100 BC.

For the first few centuries, serving in the army was part of civic duty in Rome. Poorer citizens served in the infantry, and were expected to purchase their own equipment. They were divided into three groups, the Hastati, Principes, and Triarii, organized by age. The younger Hastati served in the front line, and were generally the least well armored, as they had little money to purchase such things.The Hastati would carry spears. As men gained experience and acumulated equipment they were moved into the other ranks. Each infantry man was part of a century of 80 men, two of which formed a maniple, the common unit of maneuver. The Roman upper-middle class, or Equites, were obligated to own horses, and hence served in the cavalry. The upper class of Rome, the Senators, served as the army's leaders, serving as legates and tribunes. All of these groups together formed a legion.

During the reign of Augustus the army became a professional one. Its core was composed of Roman citizens who served for twenty five years. They often received a large pension from their general, and later from the emperor, often in the form of a grant of land in the province in which they served. These soldiers were organized differently as well, into uniform cohorts of six to eight centuries each. A legion consisted of six to ten infantry cohorts, plus cavalry, for about 4,800 men in total.

Over time these professional soldiers had less and less in common with the citizens of Rome. In the 2nd century and 3rd century A.D. this distance lead to frequent revolts as the legions began to feel that they could take power into their own hands.

Both the pre- and post-Marian armies were greatly assisted by auxilary troops. A typical Roman legion was accompanied by a matching auxilary legion. In the pre-Marian army these auxilary troops were Italians, and often Latins, from cities near Rome. The post-Marian army incorporated these Italian soldiers into its standard legions (as all Italians were Roman citizens after the Social War). Its auxilary troops were made up of foriegners from provinces distant to Rome, who gained Roman citizenship after completing their twenty five years of service. This system of foreign auxilaries allowed the post-Marian army to strengthen traditional weak points of the Roman system, such as light missile troops and cavalry, with foreign specialists.

In the Imperial period the Roman army was remarkably large, being charged with the task of guarding Rome's extensive frontier. Modern authorities estimate that between 250,000 and 300,000 soldiers were under Roman arms at any one time.

Weapons and equipment

Roman navy

History and evolution

The Roman navy was very much inferior, both in prestige and capability, to the Roman army. Before the First Punic War in 264 BC there was no Roman navy to speak of as all previous Roman war had been fought in Italy. But the war in Sicily against Carthage, a great naval power, forced Rome to quickly build a fleet and train sailors. The first few naval battles of the First Punic War were disasters for Rome, and it was not until the invention of the Corvus, a grappling engine which made it easier for Romans to board the Carthagenian vessels, that Rome was able to win the war.

The Punic wars were both the beginning and the height of the Roman navy. Rome was able to use her superior army in preference to her navy in most of the wars she fought afterwards. By the late Empire Roman control over the Mediterranean coast meant that there were no non-Roman navies to fight. Indeed, Rome's last major naval battle was fought between Romans, Octavian and Marc Antony, at Actium.

Weapons and equipment

Events

Patterns of Roman wars

The first Roman wars were wars of conquest, aimed at protecting Rome itself from neighboring cities and nations by defeating them in battle. This sort of warfare characterized the early Republican Period when Rome was focused on consolidating its position in Italy, and eventually conquering the peninsula. Rome first began to make war outside the Italian peninsula in the Punic wars against Carthage. These wars, starting in 264 BC saw Rome become a Mediterranean power, with territory in Sicily, North Africa, Spain, and, after the Macedonian wars, Greece.

While expansion continued in the late Republic, civil war became an increasingly common feature. In the last century before the common era at least 12 civil wars and rebellions occurred. These were generally started by one charismatic general who refused to surrender power to the Roman Senate, which appointed generals, and so had to be opposed by an army loyal to the Senate. This pattern did not break until Octavian, later Augustus ended it by becoming a successful challenger to the Senate's authority, and was crowned emperor.

As the emperor was a centralized authority with power focused in Rome, he was generally not able to leave the city for long periods of time to fight wars. Because he feared rebellion by powerful generals, he was not willing to appoint powerful generals. These factors lead to a dramatic slowing of acquisition of territory under the Roman Empire. Trajan was one of the few emperors of the early imperial period who was secure enough in his reign to leave Rome for long periods of time, and his rule saw the largest Roman gains of the imperial period, as he added Armenia, Parthia and Dacia as provinces to the empire.

The third century saw a crisis in roman rule when a series of weak emperors and powerful invasions by outside forces saw the empire splinter into three parts, the core loyal to Rome, the west as the Gallic Empire, and the city of Palmyra ruling over much of the east. After this crisis was resolved and the empire reunited the emperor's focus of power became the legions rather than the city of Rome. New emperors were chosen by the army, rather than by heredity or adoption. A system of four co-emperors, the Tetrarchy, was adopted, allowing one emperor to stay with the eastern legions while another stayed with the western legions. This system lasted, with a brief unification under Constantine until the end of the Western Empire, after which Roman military history becomes Byzantine military history.

List of Roman wars

Institutions

Roman army

History and evolution

Weapons and equipment

Roman navy

History and evolution

Weapons and equipment

Events

Patterns of Roman wars

List of Roman wars

Wars of conquest

Revolts and rebelions

External invasions

See also