Military establishment of the Roman kingdom

The city of Rome, founded in a strategic location among a war-like people (the Etruscans), needed to concern itself with military activity from the start. As Rome grew, its military needs changed. This article covers the Military establishment of the Roman kingdom up to about 300BC.

Initial army
Rome was probably founded as a compromise between Etruscan residents of the area and Italic tribes nearby. The kings were Etruscan. Their language was still spoken by noble families in the early empire, although sources tell us it was dying out. Under the first king, Romulus, society consisted of gentes, or clans, arranged in 80 curiae and three tribes. From them were selected 8000 pedites (infantry) and 800 celeres (cavalry) of gentes-connected men. The decimal scheme seems already to have existed: one unit of fast troops for every 10 of foot.

The Etruscans were heavily influenced by Greek culture, which can be viewed as dominating the eastern Mediterranean. At first, under the Etruscan Kings, the massive Greek phalanx was the most desired battle formation. Early Roman soldiers hence must have looked much like Greek hoplites.

Reforms of Servius Tullius
A key moment in Roman history was the introduction of the census (the counting of the people) under Servius Tullius. He had found that the aristocratic organization now did not provide enough men for defense against the hill tribes, and, consequently, he accepted non-aristocrats into the state and reorganized society on the basis of wealth, determined at the census.

Citizens were graded into six classes by property assessment. From them were recruited milities according to the equipment they could afford and the needs of the state.

From the wealthiest classes were recruited the heavy-armed infantry, equipped like the Greek hoplite warrior with helmet, round shield (clipeus), greaves and breastplate, all of bronze, and carrying a spear (hasta) and sword (not the gladius). In battle they followed the principle of "two forward, one back." The first and second acies, or lines of battle, composed of principes and hastati, were forward; the triarii or "third rank", containing the veterani, or "old ones", was held in reserve. From the name, hastati, we can deduce that the hasta, a thrusting spear, was the weapon of choice. Triarii were equipped with a long spear, or pike, a shield and heavy armor.

The remaining class or classes (rorarii) were light-armed with the javelin (verutum). They were no doubt used for skirmishing, which provided some disruption of enemy ranks before the main event.

The officers as well as the cavalry were either not in the six classes or were of the first class. The question remains open. If the nobility were above the six, they were drawn from the senatorial rank or rank of equestrians (equites), also known as knights. Cavalry remained an aristocratic arm up to the introduction of motorized warfare.

Reforms of Camillus
All in all the Roman army consisted of 18 centuries of equites, 82 centuries of the first class (of which 2 centuries were engineers), 20 centuries each of the second, third and fourth classes and 32 centuries of the fifth class (of which 2 centuries were trumpeters).

Even these measures were inadequate to the challenges Rome was to face. They went to war with the Hernici, Volsci and Latini (Italics), undertook the reduction of Etruria and endured an invasion of Gauls under Brennus. Into the gap stepped one of the great generals Rome seemed able to produce at critical moments: Marcus Furius Camillus. He held various offices, such as interrex and dictator, but was never king himself.

In the early fourth century BC Rome received its greatest humiliation, as Po valley Celts under Brennus sacked Rome itself. The Romans wanted to abandon the city and resettle at Veii (an Etruscan city), but Camillus prevented it. If Rome was to re-establish her authority over central Italy, and be prepared to meet any similar disasters in future, some reorganization was needed. These changes were traditionally believed to have been the work of Camillus, but in another theory they were introduced gradually during the second half of the fourth century BC.

Italy was not governed by city states like Greece, where armies met on large plains, deemed suitable by both sides, to reach a decision. Far more it was a collection of hill tribes using the difficult terrain to their advantage. Something altogether more flexible was needed to combat such foes than the unwieldy, slow-moving phalanx.

The legio, or "levy", was introduced at this time, with a structure of manipuli ("handsful"). The infantry adopted a looser fighting formation distinct from the earlier tightly packed hoplite shield wall, and soldiers began to carry javelins. In this formation the Romans became more like their Gallic adversaries than Greek hoplites.