I've read some about both the Roman army and the Late Republican period, but realized that, while I understand well enough how legions worked in the field, I have only a very incomplete idea of who could actually raise them in the post-Marian pre-Principate army. In other words, who had the authority to do it, how did get that right, what if any political and religious hoops did they have to jump through, and how and when was the process subverted? For example, clearly consuls and proconsuls could raise legions, did the right stop with them?

A search of wikipedia and the ancient history encyclopedia turned up a scattering of useful information, but nothing that I felt that I could piece together into a systemic overview, however abbreviated. I'm interested in not just legions proper, but any Late Republican post-Marian military force capable of taking to the field. Thanks for your time.

2 Answers 2


Through the entire Republican era only Imperium-holding Magistrates of the Roman People were able to lawfully raise an army of citiziens. (a legion)

Private individuals could also form fighting forces from their slaves, clients or hired gladiators. That was sort of borderline, but happened quite often in the civil-strife ridden decades of the late republic.

But to raise a legion (or a serious auxiliary force from some client state or ally) one needed imperium. So either he had to be elected as consul or praetor, appointed dictator, given proconsular/propraetorian province after the magistral year, or conferred some special command by the vote of the People. (like the maritime super-command Pompeius got against the pirates)

So to get a legion, one should usually win some election, and then be properly inaugurated into command under the right rituals. There were some other restrictions, like one had to be of required age to be eligible to election, and after the proper election, one theoretically needed lex curiata de imperio too, but these could usually be bypassed by willpower and political support.

Under normal circumstances and dutiful conduct even magistrates would only conscript legions after consulting the Senate and reciving the decree of the Fathers that this is necessary for the public good, but proconsuls sent to remote and barbarian provinces could act more or less on their own discretion, even more so after they seriously started to pursue ambitions of power: look at the case of Caesar, he happily levied two legions in Cisalpine Gaul when he perceived/claimed that war threatened in his province (book 1, section 10, CdBG) and later could freely demand horsed auxiliaries from the newly conquered peoples.

EDIT: On appointing promagistrates:

Under ancient custom and religious taboo only the consuls (and dictators in special case) possessed the full ius auspicium - the power to consult the gods on questions of war - and they were the only ones authorized to lead a whole army against the enemies of the Roman People.

When in 327 Publilius Philo's consular year terminated while an important siege was underway, the romans turned to legal fiction: The Senate decreed that he could retain his command, acting 'pro consules' - that is, in place of the consuls.

As Rome obtained overseas territories and organized provinces, need arised for authorized commanders at every frontier. (while actual praetors and consuls had quite enough work in Italy) The exception became norm.

By the time of Caesar it was expected and almost self-evident that the major magistrates would each get one province to govern after their magistarial year was over.

Often they drew lots to distribute the governorships, although smaller and non-frontier provinces like Sicily would usually go to propraetors. On occassions the vote of the Senate had a say in the distribution, and the duration could vary: one year was normal but powerful and aggressive politicians could get five.

So in fact promagistrates were never properly integrated into the roman constitution (of course there was no such text, only customs and best practices inherited from the ancestors), and some say (like Machiavelli) that this contributed greatly to the fall of the Republic.

  • Hey, I wanted to ask a clarifying question if you have a second: I'm reading up on the powers and titles you listed and trying to find out which assembly could vote to extend a magistrate's power and make them a promagistrate. Wikipedia only mentions a "Popular Assembly" which weirdly links to a modern socialist group XD , Do they mean the Committee Centuriata?
    – Random
    Commented Jun 21, 2018 at 0:56
  • 1
    No, while the main assembly was indeed the Committee Centuriata (that could pass laws, elect consuls and declare war), I would guess that under Popular Assembly they would mean the Concilium Plebis (Plebeian Council) But it was not the Plebeian Council that made promagistrates: weirdly enough, the Senate could make them.
    – b.Lorenz
    Commented Jun 21, 2018 at 6:20

As I remember, Marcus Licinius Crassus was quoted as saying a man shouldn't go into politics unless he could afford to maintain at least one legion. Or maybe it was a higher number of legions.

Either Crassus meant that someone wealthy enough to be a politician would be wealthy enough to pay all the costs, including necessary permits and legal fees, of raising and maintaining a legion whenever necessary, or else that a politician who was wealthy enough could raise and maintain a legion on his own authority without permission from any higher authority.

As I remember, once a Roman civil war began, one side or both sides sometimes raised new legions to increase their forces. And it seems to me that in such situations at lest one side would be doing so without any legal authority or justification.

So I don't know, but it seems likely that during Roman civil wars at least once side would have no legal justification (though it might try to make something up) for raising additional legions and thus that sometimes legions were raised without permission from higher authority.

  • 3
    This, I read as ranging from a bit to very vague. References? These might ease. Commented Jun 19, 2018 at 21:01
  • 1
    I read that as ensuring he has a suitably large military force to protect them/enforce his vision
    – user17382
    Commented Jun 20, 2018 at 4:14
  • 2
    That doesn't answer the question at all.
    – Jos
    Commented Jun 20, 2018 at 6:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.