Roman army of the mid-Republic in the context of "Principes"

The Punic Wars were a series of wars fought between the Roman Republic and the Carthaginian Empire during the period 264 to 146 BC. Three such wars took place, involving a total of forty-three years of warfare on both land and sea across the western Mediterranean region, and a four-year-long revolt against Carthage.

The First Punic War broke out on the Mediterranean island of Sicily in 264 BC as a result of Rome's expansionary attitude combined with Carthage's proprietary approach to the island. At the start of the war Carthage was the dominant power of the western Mediterranean, with an extensive maritime empire (a thalassocracy), while Rome was a rapidly expanding power in Italy, with a strong army but no navy. The fighting took place primarily on Sicily and its surrounding waters, as well as in North Africa, Corsica and Sardinia. It lasted twenty-three years, until 241 BC, when the Carthaginians were defeated. By the terms of the peace treaty Carthage paid large reparations and Sicily was annexed as the first Roman province. The end of the war sparked a major but eventually unsuccessful revolt within Carthaginian territory known as the Mercenary War.

The Battle of Cannae (/ˈkæni, -eɪ, -aɪ/; Latin: [ˈkanːae̯]) was a key engagement of the Second Punic War between the Roman Republic and Carthage, fought on 2 August 216 BC near the ancient village of Cannae in Apulia, southeast Italy. The Carthaginians and their allies, led by Hannibal, surrounded and practically annihilated a larger Roman and Italian army under the consuls Lucius Aemilius Paullus and Gaius Terentius Varro. It is regarded as one of the greatest tactical feats in military history and one of the worst defeats in Roman history, and it cemented Hannibal's reputation as one of antiquity's greatest tacticians.

Having recovered from their losses at Trebia (218 BC) and Lake Trasimene (217 BC), the Romans decided to engage Hannibal at Cannae, with approximately 86,000 Roman and allied socii troops. They massed their heavy infantry in a deeper formation than usual, while Hannibal used the double envelopment tactic and surrounded his enemy, trapping the majority of the Roman army, who were then slaughtered. Later historians and military strategists have used Cannae as an exemplary battle of annihilation. The loss of life on the Roman side meant it was one of the most lethal single days of fighting in history; historian Adrian Goldsworthy equates the death toll at Cannae to "the massed slaughter of the British Army on the first day of the Somme offensive in 1916". Only about 15,000 Romans, most of whom were from the garrisons of the camps and had not taken part in the battle, survived. Following the defeat, Capua and several other Italian city-states defected from the Roman Republic to Carthage.

The Roman army of the late Republic refers to the armed forces deployed by the late Roman Republic, from the beginning of the first century BC until the establishment of the Imperial Roman army by Augustus in 30 BC.

Shaped by major social, political, and economic change, the late Republic saw the transition from the Roman army of the mid-Republic, which was a temporary levy based solely on the conscription of Roman citizens, to the Imperial Roman army of the Principate, which was a standing, professional army based on the recruitment of volunteers.

Velites (Latin: [ˈweːlɪteːs]; sg.: veles) were a class of infantry in the Roman army of the mid-Republic from 211 to 107 BC. Velites were light infantry and skirmishers armed with javelins (Latin: hastae velitares), each with a 75cm (30 inch) wooden shaft the diameter of a finger, with a 25cm (10 inch) narrow metal point, to fling at the enemy. They also carried short thrusting swords, or gladii, for use in melee. They rarely wore armour as they were the youngest and poorest soldiers in the legion and could not afford much equipment, but they did carry small wooden shields called parma for protection. The velites were placed at the front partly for tactical reasons, and also so that they had the opportunity to secure glory for themselves in single combat.

Velites did not form their own units; a number of them were attached to each maniple of hastati, principes and triarii. They were typically 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 normally 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 approximately 1000 velites. Velites were disbanded after the so-called "Marian reforms". Lucilius suggests that rorarii and velites were interchangeable, with velites gradually superseding rorarii. Another theory is that the leves' equipment was upgraded until they were at the same level as the rorarii, and they both collectively became known as the velites.