Editing Roman army (section)

== Early Roman army (c. 550 – c. 300 BC) ==
{{main|Early Roman army}}

Until {{circa|550 BC}}, there was no "national" Roman army, but a series of clan-based war-bands which only coalesced into a united force in periods of serious external threat. Around 550 BC, during the period conventionally known as the rule of king [[Servius Tullius]], it appears that a universal levy of eligible adult male citizens was instituted. This development apparently coincided with the introduction of heavy armour for most of the infantry. Although originally low in numbers, the Roman infantry was extremely effective and developed some influential battle strategies.

The early Roman army was based on a compulsory levy from adult male citizens which was held at the start of each campaigning season, in those years that war was declared. There were no standing or professional forces. During the [[Roman Kingdom|regal period]] (to c. 500 BC), the standard levy was probably of 9,000 men, consisting of 6,000 heavily armed infantry (probably Greek-style [[hoplites]]), plus 2,400 light-armed infantry (''[[rorarii]]'', later called ''[[velites]]'') and 600 light cavalry ({{Lang|la|equites celeres}}). When the kings were replaced by two annually elected ''[[praetor]]es'' in c. 500 BC, the standard levy remained of the same size, but was now divided equally between the praetors, each commanding one [[Roman legion|legion]] of 4,500 men.

It is likely that the hoplite element was deployed in a Greek-style [[phalanx formation]] in large [[Pitched battle|set-piece battles]]. However, these were relatively rare, with most fighting consisting of small-scale border-raids and skirmishing. In these, the Romans would fight in their basic tactical unit, the ''[[centuria]]'' of 100 men. In addition, separate clan-based forces remained in existence until {{circa|450 BC}} at least, although they would operate under the Praetors' authority, at least nominally.

In 493 BC, shortly after the establishment of the [[Roman Republic]], Rome concluded a perpetual treaty of military alliance (the ''[[Foedus Cassianum]]''), with the combined other [[Latins (Italic tribe)|Latin]] city-states. The treaty, probably motivated by the need for the Latins to deploy a united defence against incursions by neighbouring hill-tribes, provided for each party to provide an equal force for campaigns under unified command. It remained in force until 358 BC.