Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
Civil and Military Authority
It was at this period, finally, that the provinces of civil and military authority were separated. In the former the law ruled, in the latter the axe: the former was governed by the constitutional checks of the right of appeal and of regulated delegation; in the latter the general held an absolute sway like the king.(15)
15. It may not be superfluous to remark, that the -iudicium legitimum-, as well as that -quod imperio continetur-, rested on the imperium of the directing magistrate, and the distinction only consisted in the circumstance that the -imperium- was in the former case limited by the -lex-, while in the latter it was free.
It was an established principle, that the general and the army as such should not under ordinary circumstances enter the city proper. That organic and permanently operative enactments could only be made under the authority of the civil power, was implied in the spirit, if not in the letter, of the constitution.
Instances indeed occasionally occurred where the general, disregarding this principle, convoked his forces in the camp as a burgess assembly, nor was a decree passed under such circumstances legally void; but custom disapproved of such a proceeding, and it soon fell into disuse as though it had been forbidden. The distinction between Quirites and soldiers became more and more deeply rooted in the minds of the burgesses.
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Reference address : https://www.ellopos.net/elpenor/rome/2-01-constitution-magistrate.asp?pg=32