Editing Roman legion (section)

=== Late Republic (107–27 BC) ===
{{Main|Roman army of the late Republic}}
{{Hatnote|See also [[List of Roman legions]] for details of notable late Republican legions<br />
See also [[List of Roman army unit types#Sub-Units of the Roman legion|Sub-Units of the Roman legion]]}}
[[File:Legion Task ORG.png|thumb|500px|Visual representation of the legion showing size and disposition for Infantry formations]]

Each century had its own standard and was made up of ten units (''[[Contubernium (Roman army unit)|contubernia]]'') of eight men who shared a tent, a millstone, a mule and [[Cookware and bakeware|cooking pot]].

Full Roman citizenship was open to all the regions of Italy. At the same time, the three different types of heavy infantry were replaced by a single, standard type based on the ''principes'': armed with two heavy javelins called ''pila'' (singular ''[[pilum]]''), the short sword called ''gladius'', chain mail (''[[lorica hamata]]''), helmet and rectangular shield (''[[scutum]]'').

The role of allied legions would eventually be taken up by contingents of allied auxiliary troops, called ''auxilia''. ''Auxilia'' contained ''[[immunes]]'' (specialist units), engineers and pioneers, artillerymen and craftsmen, service and support personnel and irregular units made up of non-citizens, mercenaries and local militia. These were usually formed into complete units such as light cavalry, [[light infantry]] or ''[[velites]]'', and labourers. There was also a [[reconnaissance]] [[squad]] of ten or more light [[mounted infantry]] called ''[[speculatores]]'', who could also serve as messengers or even as an early form of [[military intelligence]] service.

A typical legion of this period had 5,120 legionaries as well as a large number of camp followers, servants and slaves. Legions could contain as many as 11,000 fighting men when including the auxiliaries. During the Later Roman Empire, the legion was reduced in size to 1,000 to allow for easier provisioning and to expand the regions under surveillance. Numbers would also vary depending on casualties suffered during a campaign; [[Julius Caesar]]'s legions during his campaign in Gaul often only had around 3,500 men.

Tactics were not very different from the past, but their effectiveness was largely improved because of the professional training of the soldiers.

Throughout the history of Rome's Late Republic, the legions played an important political role. By the 1st century BC, the threat of the legions under a [[demagogue]] was recognised. [[Roman governor]]s were not allowed to leave their provinces with their legions. When [[Julius Caesar]] broke this rule, leaving his province of Gaul and crossing the Rubicon into Italy, he precipitated a [[constitutional crisis]]. This crisis and the [[List of Roman civil wars and revolts|civil wars]] which followed brought an end to the Republic and led to the foundation of the [[Roman Empire|Empire]] under [[Augustus]] in 27 BC.