Roman military expansion

[munifex]

Hi im Sean, im new to the site. I have a passion for ancient Romans. Well I was thinking why in the roman republic did they seem to expand more than the time of the Principate? I believe its because the emperors were insecure and didn't want generals to get to popular. Were in the republic you had alot of skilled generals and they were aloud to flourish. But I want to know why the emperors didn't expand the empire greatly?

[AMELIANVS]

Hi Sean,
you are right in that most emperors dont like too much popular or too powerfull generals,but in generall terms Republican rome had a lot of "civilized"territory around Mediterranean Sea to expand,with developed economies,cities to hold, and so on.When Empire emerged, they had already reached territories which were lacking this kind of infrastructure(with some notable exceptions of course),and also reached limits of what they were able to effectively control.Moreover-feeling this, emperors like Augustus and Hadrian didnt even want to expand the Empire any significantly anymore.They want it as it was, in the frontiers they believed are good to mantain and defend and not overstretching their powers.Romans always believed that once they wuld be secure enough another great conquest to the north and est will come in time.

[M. Demetrius]

Under Augustus through Titus, the Empire reached the limit of the supply line distances that it could sustain. They could have conquered Central Africa, but what would be their reason? There wasn't much there to tax, mine or harvest.

Perhaps they could have conquered into Germany and Scandanavia, but the climate was hostile to them, and there was little to gain at that time. The mineral stores of iron, coal, etc., were unknown in that day.

The difficulty they faced has more to do with keeping territory than acquiring territory. That's the way I see it anyhow.

[munifex]

I guess that only parthia was tempting to the Romans as at the time of the early empire was the only major threat to rome. There was certainly alot of wealth in parrthia as I think it was on a major silk routes. Also alot of generals including ceasar inspired to be like Alexander the great who brought down the mighty Persians and parthia was roughly equivalent to the Persian empire.

[Epictetus]

There were some attempts to expand under the Emperors. Britain was taken during the Principate, for example, and Trajan tried some major expansions. There is even a possibility Marcus Aurelius planned two new provinces during his northern wars. Some of this was defensive expansion, to stop incursions, and wasn't quite undertaken with a conquest mindset.

[Eleatic Guest]

Well I was thinking why in the roman republic did they seem to expand more than the time of the Principate?

This is because the empire of the Principate was larger and felt the constraints of space and logistics more.

I have observed this effect also in realistic computer strategy games. From a certain point on, the expansion begins to slow and one becomes more and more bogged down in keeping together what one has achieved. Experiencing this phenomenon first-hand, if only virtually, was a better teacher than many a history book.

Keywords you may want to look up are are imperial (over)stretch and, in a narrower, military sense, advantage of the inner line.

[Sardaukar]

If I recall correctly, Britain required 3-4 legions and 66 auxiliary cohorts to keep pacified. Dacia required 2 legions and 44 auxiliary cohorts. I just was not necessarily economical to keep expanding.