This is obviously wrong. No sane person would argue that climate change in Roman times was man-made, therefore there was no possible action Rome could have taken to mitigate it.
Isn’t the bigger point that the modern world is in a situation to mitigate climate change, but isn’t really trying enough, thus risking the same fate as the Roman Empire?
Plus capturing more water, diverting water, those are things that can address lack of rain. Grow crops that use less rain per produced food. There are endless things man can to do counter natural events. For us, besides all those things, don't build in flood plains, don't build in the forest that has frequent fires (probably most of them). or build houses that won't be destroyed by fires. http://abcnews.go.com/US/mans-concrete-home-survives-raging-...
Yes the article is written like if environmental changes were the only factor. It may very well have undermined the inner streng of the empire (as a child I learn about the lead pipes that would have been a major issue because of saturnism) but it still needed external interventions to collapse. The article even mention the Byzantine Empire which have a very clear date and cause of falling that is definitely not climate related.
The chief culprit was permitting tens of thousands of barbarians to enter the empire. They never integrated or left. Within a hundred years, the western part of the empire collapsed. https://en.wikipedia.org/wiki/Gothic_War_(376–382)
In fact, one of the Roman demands permitting their emigration was that they surrender the children of the wealthy and powerful to be raised as Romans; this hostage-taking as typical of the times and an effective means of assimilation and integration, as the children generally returned home with Roman ideas in their head.
The immediate cause of the first Gothic revolt was that the Romans simply could not logistically supply the massive number of Goths, the Goths bribed their way out of surrendering their arms as they were required to do, and when the (hungry) Goths encountered a town market they were not allowed to go to (so as to not drive up food prices for local citizens to exorbitant prices), they decided to take what they wanted by force, killing anyone in the way. Then when the Romans attempted to punish them, they decided all agreements were off.
They had let tens of thousands of outsiders in before without issue. The difference here was the Goths beat the Romans on the field, forcing Rome to accept a bad deal. This was a result of a long period of famine and pestilence creating budget problems, leaving provinces to go into revolt, and the army stretched too thin to deal with everything.
The Gothic emigration much more resembled the emigration of the Cimbri or the Teutons than it did the resettlement of a few ten thousand peoples around the empire.
The Goths were relatively barbarian, fundamentally hostile to the empire except in the dire emergency precipitated by the Huns, and further, the original Gothic revolt predated the problems you're talking about and the defeat of the Romans in the field.
It was also almost certainly much more than a few ten thousands, despite the usual tactic of modern historians who downplay numbers in general with handwavy arguments about how that's just not possible, etc. and discount the accounts of contemporary sources without any hard evidence contradicting them.
> It was thought expedient that an accurate account should be taken of their numbers; but the persons who were employed soon desisted, with amazement and dismay, from the prosecution of the endless and impracticable task;(67) and the principal historian of the age most seriously affirms that the prodigious armies of Darius and Xerxes, which had so long been considered as the fables of vain and credulous antiquity, were now justified, in the eyes of mankind, by the evidence of fact and experience. A probable testimony has fixed the number of the Gothic warriors at two hundred thousand men; and if we can venture to add the just proportion of women, of children, and of slaves, the whole mass of people which composed this formidable emigration must have amounted to near a million of persons, of both sexes and of all ages.
If they had numbered only a few ten thousand, the Roman logistics system would not have struggled so much to keep them fed, nor would it have been a major problem to account for them all.
>The Goths were relatively barbarian, fundamentally hostile to the empire except in the dire emergency precipitated by the Huns, and further, the original Gothic revolt predated the problems you're talking about and the defeat of the Romans in the field
The Goths were a major part of the Roman army for a century before the uprising discussed, and the famine and pestilence were also becoming a major issue around the same time. And the Goths were no more barbarian than much of Caesar's army, their hostility came from the overall problems the empire faced.
>If they had numbered only a few ten thousand, the Roman logistics system would not have struggled so much to keep them fed, nor would it have been a major problem to account for them all.
The empire was struggling to feed itself, even a relatively small number of people in one area can cause problems. And the contemporary sources are dismissed because we know the things written down are propaganda based largely on guesswork. Modern historians realize a million people suddenly showing up would leave a massive archaeological record that isn't there.
> The Goths were a major part of the Roman army for a century before the uprising discussed
Different Gothic tribes cannot be conflated. Also important to note is that the 'Romanized' Goths only became so because they devastated, conquered and kept Roman territory - they weren't friendly settlers, they were neighbors the Romans had to learn how to deal with and use against other enemies.
> And the famine and pestilence were also becoming a major issue around the same time.
Not until later, and then in part because of Gothic devastation. If the Roman Empire had not been able to feed a few ten thousand armed people, it would have fallen nearly immediately, since that would have meant it would have been unable to field any significant armies.
> Modern historians realize a million people suddenly showing up would leave a massive archaeological record that isn't there.
It is.
Further, it's very hard to explain why it'd be hard to census only 90k people, an activity performed regularly.
>Not until later, and then in part because of Gothic devastation. If the Roman Empire had not been able to feed a few ten thousand armed people, it would have fallen nearly immediately, since that would have meant it would have been unable to field any significant armies.
The Crisis of the Third Century is what lead to the weakened state unable to cope with the Goths. Outside invasions were part of the problem, the Plague of Cyprian was a much larger part. The breakdown that occurred during this period led to widespread problems, they trade routes were damaged making it difficult to suddenly feed an unexpected influx of people.
>Further, it's very hard to explain why it'd be hard to census only 90k people, an activity performed regularly.
First, there wasn't a ton of time between their arrival and their revolt to count them. Second, the census had suffers a long period of decay by that point. Third, counting nomads is no easy work, and the general strategy of assessing taxes based on property didn't apply yet.
The Goths were driven into the empire by the Huns.
Nor, as other commenters said, had the Romans permitted anything like it before.
> But the attention of the emperor was most seriously engaged by the important intelligence which he received from the civil and military officers who were intrusted with the defence of the Danube. He was informed that the North was agitated by a furious tempest; that the irruption of the Huns, an unknown and monstrous race of savages, had subverted the power of the Goths; and that the suppliant multitudes of that warlike nation, whose pride was now humbled in the dust, covered a space many miles along the banks of the river. With outstretched arms and pathetic lamentations they loudly deplored their past misfortunes and their present danger; acknowledged that their only hope of safety was in the clemency of the Roman government; and most solemnly protested that, if the gracious liberality of the emperor would permit them to cultivate the waste lands of Thrace, they should ever hold themselves bound, by the strongest obligations of duty and gratitude, to obey the laws and to guard the limits of the republic. These assurances were confirmed by the ambassadors of the Goths, who impatiently expected from the mouth of Valens an answer that must finally determine the fate of their unhappy countrymen. The emperor of the East was no longer guided by the wisdom and authority of his elder brother, A.D. 375, Nov 17.whose death happened towards the end of the preceding year; and as the distressful situation of the Goths required an instant and peremptory decision, he was deprived of the favourite resource of feeble and timid minds, who consider the use of the dilatory and ambiguous measures as the most admirable efforts of consummate prudence. As long as the same passions and interests subsist among mankind, the questions of war and peace, of justice and policy, which were debated in the councils of antiquity, will frequently present themselves as the subject of modern deliberation. But the most experienced statesman of Europe has never been summoned to consider the propriety or the danger of admitting or rejecting an innumerable multitude of barbarians, who are driven by despair and hunger to solicit a settlement on the territories of a civilised nation. When that important proposition, so essentially connected with the public safety, was referred to the ministers of Valens, they were perplexed and divided; but they soon acquiesced in the flattering sentiment which seemed the most favourable to the pride, the indolence, and the avarice of their sovereign. The slaves, who were decorated with the titles of praefects and generals, dissembled or disregarded the terrors of this national emigration—so extremely different from the partial and accidental colonies which had been received on the extreme limits of the empire.
Actually, the chief culprit was permitting tens of thousands of fusion-guitar players to enter the empire. My feelings about fusion-guitarists have nothing to do with that fact.
A civilizational collapse is rarely caused by a single event, but instead by multiple events - each which would be survivable on their own - causing a complete breakdown in the system. A society can survive a drought, a war, a plague, a famine, but all four at once might just be too much.
It's not for want of a nail that a kingdom is lost, but because of all accumulated failures and breakdowns which led to the point where loss of a single nail was just that one failure too much. Death by drowning in a million raindrops.
"From the eighteenth century onward, we have been obsessed with the fall: it has been valued as an archetype for every perceived decline, and, hence, as a symbol for our own fears."
~ Glen Bowersock
The most important reason for the fall of Rome is frankly obvious, so obvious it's never mentioned: the severe political divisions within the Empire which caused it to fracture. The bulk of the intellectual and economic power in Rome shifted to the Eastern Empire, which lasted in its original form until the eighth century, and in some form until the fifteenth. The seeds of the fall of the Western Roman Empire in the fifth century were sown when Theodosius divided the Empire among his sons in 395, and there is hardly any comparable event today. There were various other reasons, of course; disease certainly didn't help, neither did the appearance of the Sassanids, the increasing irrelevance of the Senate, or famines in Gaul. But everyone on the right and the left wants Rome to have fallen because of its mishandling of their favorite political issue, be it inflation, military conscription, climate change, taxation, or as one amusingly inaccurate meme charges, religious intolerance. These accusations are all silly. The Roman Empire saw multiple civil wars between the reign of Constantine and the conquest by Odoacer. No developed country today faces such an issue. As soon as it was no longer able to draw support from the East, the Western Roman Empire began eighty years of monotonic decline.
If there is any moral to the story, it's that monarchy is unsustainable -- but we all knew that, anyway.
>The Roman Empire saw multiple civil wars between the reign of Constantine and the conquest by Odoacer.
We may not see that today, but that was fairly common for Rome. Marius and Sulla's civil wars, Caesar's civil wars, and Octavian's civil wars all took place in a century. And chalking it all up to "monarchy is unstable" ignores the collapse of the Republic and the 4-15 centuries that the monarchy did pretty well.
I didn't mean that the civil wars were the primary cause of decline (although they helped) but that they serve to distinguish the Roman Empire from modern countries and weaken the possibility of comparison. My point is really that the Western Roman Empire never had a chance -- Rome started in southern Italy and expanded because its early enemies didn't recognize it as a threat, but they couldn't get away with that again, of course.
As to whether the monarchic system was the reason Rome couldn't keep the whole Empire under one roof -- well, the Byzantines lasted, but they did so while controlling much less territory (Justinian's conquests were quickly lost), so while my argument is weak, I admit, your counterexample is also. The monarchy was successful from
Octavian until Commodus; after that, it is hard to name two good rulers who succeeded each other, and impossible to name three. I think it is not by accident that during this early period the Senate was still politically relevant and vaguely democratic. But I am also just strongly tempted to blame regional divisions on poor governance, although there were probably other factors, and I am hardly a scholar.
"It never had a chance" was a five century long empire. Sure it was destined to fall, but that's the nature of empire so far, which invited comparison to modern times. And your description of the early expansion somewhat works for the conquest of Italia, but after that they were considered a threat.
>I think it is not by accident that during this early period the Senate was still politically relevant and vaguely democratic.
The senate had no actual power starting with Augustus, who turned it into a ceremonial institution. The only time it did have a shred of power was a succession crisis, and it maintained that power throughout.
>But I am also just strongly tempted to blame regional divisions on poor governance, although there were probably other factors,
The Western Roman Empire existed on its own for 83 years, not 500. It split off in 393 with the death of Theodosius and was conquered by Odoacer in 476. That's hardly longevity.
>The senate had no actual power starting with Augustus, who turned it into a ceremonial institution.
Early Emperors cared what the Senate thought, even if they didn't have to. Later ones didn't.
>Around 300 AD, the emperor Diocletian enacted a series of constitutional reforms. In one such reform, he asserted the right of the emperor to take power without the theoretical consent of the senate, thus depriving the senate of its status as the ultimate depository of supreme power. Diocletian's reforms also ended whatever illusion had remained that the senate had independent legislative, judicial, or electoral powers. The senate did, however, retain its legislative powers over public games in Rome, and over the senatorial order.
Unfortunately, science journalism tends to fail to capture the role that books like this play in academic history. I doubt that the author says that climate was a leading factor in Rome's fall, but I'm sure he makes a strong argument that we should not neglect its role.
It's important in the sense that it investigates a typically neglected dimension, but I think historians will be hesitant to rank factors that led to the fall. Sufficiently self-aware historians are aware that the etiology of past events is a tricky business, and the best one can do is discuss a sequence of events with great detail that may or may not be linked by causation.
If you know historians, you'll know they actually squabble like children over stuff like this. Of course, No True Historian would ignore the role of climate in causing radiating invasion waves. Even if it was a cold day making Attila mad, it's still an equal factor.
Rome devolved into a multicultural empire where the elites imported foreign tribes to provide cheap labor, usury was rampant and the native stock stopped having children.
2. It never involves the state of the monetary policy in place
Quick bit of evidence, the Roman government pursued fast and loose debasement of their currency to prop up their heavy spending and terrible policies. Meaning, they were “printing too many coins” by diluting the amount of precious metal in each coin.
Emperors got loose printing money to support a heavy military spending to gain power and support from them. As seen in modern countries once hyper inflation hits, its game over.
Is it possible that 2 is a consequence of other factors? Like climate change or some other combinations of forces? Was the economy unable to support the number of forces due to climate change and as a result debasement of currency was seen as the best way forward?
Hyperinflation wasn’t game over for Germany. It had a brief empire shortly after it’s hyperinflation period.
Yes, but they are tied! I can't remember which emperor said something along the lines of "as long as i have the army behind me", but the scales had been tipping beyond the balance between gov / private citizens.
I think its hard to find out which came first, but the moment the government started minting 99% gold coin (and they got away with it) -> 95% gold -> 90% gold till its a worthless "gold" coin too many bad things got put in motion.
I do agree its a confluence of factors. Maybe they expanded too much -> need more money -> print money -> cant exactly fire all the expeditionary forces -> print more money -> squeeze taxes out of populace -> people are getting fed up so output and tax revenues go down -> empire is too big -> attacks on Germany and Europe from the barbarians -> print more money to pay military -> squeeze people - > ad nauseum.
There's an established economic principle that "bad money drives out good". So while I do not think that just printing money is the only cause, once it occurs its down hill. You have to somehow figure out how you will try and reign it all in (thats what they tell themselves at least).
As to the Germany example, the hyper inflation can be fixed though who can really tell how traumatizing and painful it can be to those going through it. For sure it caused some discord and animosity and some people attribute it to the rise of Hitler and so forth.
My point generally is that historians should look at the entirety of factors and weigh them together. It is all too easy to point a quick finger at the military expansion, or climate or whatever and not combine them all. Very few places look at monetary theory probably because its relatively new (really with Friedman's work in middle 20th century), but also because it muddles the simplistic reason.
Rome was built on conquest and ran out of adjacent countries to plunder. Serious problems handling environmental and political challenges didn't come up until after economic stagnation had set in.
I like to think of the fall of empires on two levels. On the level of specifics, I would suppose there are in each case generally a number of different causes, interacting in various ways.
On a more general level, empires as such are an unnaturally large and complex form of social organization, and for that reason they inevitably collapse at some point or another.
43 comments
[ 9.7 ms ] story [ 938 ms ] threadFor example, rain is not caused by human activity, and yet man-made roofs still work.
The immediate cause of the first Gothic revolt was that the Romans simply could not logistically supply the massive number of Goths, the Goths bribed their way out of surrendering their arms as they were required to do, and when the (hungry) Goths encountered a town market they were not allowed to go to (so as to not drive up food prices for local citizens to exorbitant prices), they decided to take what they wanted by force, killing anyone in the way. Then when the Romans attempted to punish them, they decided all agreements were off.
The Goths were relatively barbarian, fundamentally hostile to the empire except in the dire emergency precipitated by the Huns, and further, the original Gothic revolt predated the problems you're talking about and the defeat of the Romans in the field.
It was also almost certainly much more than a few ten thousands, despite the usual tactic of modern historians who downplay numbers in general with handwavy arguments about how that's just not possible, etc. and discount the accounts of contemporary sources without any hard evidence contradicting them.
> It was thought expedient that an accurate account should be taken of their numbers; but the persons who were employed soon desisted, with amazement and dismay, from the prosecution of the endless and impracticable task;(67) and the principal historian of the age most seriously affirms that the prodigious armies of Darius and Xerxes, which had so long been considered as the fables of vain and credulous antiquity, were now justified, in the eyes of mankind, by the evidence of fact and experience. A probable testimony has fixed the number of the Gothic warriors at two hundred thousand men; and if we can venture to add the just proportion of women, of children, and of slaves, the whole mass of people which composed this formidable emigration must have amounted to near a million of persons, of both sexes and of all ages.
http://www.ccel.org/g/gibbon/decline/volume1/chap26.htm#goth
If they had numbered only a few ten thousand, the Roman logistics system would not have struggled so much to keep them fed, nor would it have been a major problem to account for them all.
The Goths were a major part of the Roman army for a century before the uprising discussed, and the famine and pestilence were also becoming a major issue around the same time. And the Goths were no more barbarian than much of Caesar's army, their hostility came from the overall problems the empire faced.
>If they had numbered only a few ten thousand, the Roman logistics system would not have struggled so much to keep them fed, nor would it have been a major problem to account for them all.
The empire was struggling to feed itself, even a relatively small number of people in one area can cause problems. And the contemporary sources are dismissed because we know the things written down are propaganda based largely on guesswork. Modern historians realize a million people suddenly showing up would leave a massive archaeological record that isn't there.
Different Gothic tribes cannot be conflated. Also important to note is that the 'Romanized' Goths only became so because they devastated, conquered and kept Roman territory - they weren't friendly settlers, they were neighbors the Romans had to learn how to deal with and use against other enemies.
> And the famine and pestilence were also becoming a major issue around the same time.
Not until later, and then in part because of Gothic devastation. If the Roman Empire had not been able to feed a few ten thousand armed people, it would have fallen nearly immediately, since that would have meant it would have been unable to field any significant armies.
> Modern historians realize a million people suddenly showing up would leave a massive archaeological record that isn't there.
It is.
Further, it's very hard to explain why it'd be hard to census only 90k people, an activity performed regularly.
The Crisis of the Third Century is what lead to the weakened state unable to cope with the Goths. Outside invasions were part of the problem, the Plague of Cyprian was a much larger part. The breakdown that occurred during this period led to widespread problems, they trade routes were damaged making it difficult to suddenly feed an unexpected influx of people.
>Further, it's very hard to explain why it'd be hard to census only 90k people, an activity performed regularly.
First, there wasn't a ton of time between their arrival and their revolt to count them. Second, the census had suffers a long period of decay by that point. Third, counting nomads is no easy work, and the general strategy of assessing taxes based on property didn't apply yet.
Like the Vikings, the Romans were at their zenith during a warming period.
Nor, as other commenters said, had the Romans permitted anything like it before.
> But the attention of the emperor was most seriously engaged by the important intelligence which he received from the civil and military officers who were intrusted with the defence of the Danube. He was informed that the North was agitated by a furious tempest; that the irruption of the Huns, an unknown and monstrous race of savages, had subverted the power of the Goths; and that the suppliant multitudes of that warlike nation, whose pride was now humbled in the dust, covered a space many miles along the banks of the river. With outstretched arms and pathetic lamentations they loudly deplored their past misfortunes and their present danger; acknowledged that their only hope of safety was in the clemency of the Roman government; and most solemnly protested that, if the gracious liberality of the emperor would permit them to cultivate the waste lands of Thrace, they should ever hold themselves bound, by the strongest obligations of duty and gratitude, to obey the laws and to guard the limits of the republic. These assurances were confirmed by the ambassadors of the Goths, who impatiently expected from the mouth of Valens an answer that must finally determine the fate of their unhappy countrymen. The emperor of the East was no longer guided by the wisdom and authority of his elder brother, A.D. 375, Nov 17.whose death happened towards the end of the preceding year; and as the distressful situation of the Goths required an instant and peremptory decision, he was deprived of the favourite resource of feeble and timid minds, who consider the use of the dilatory and ambiguous measures as the most admirable efforts of consummate prudence. As long as the same passions and interests subsist among mankind, the questions of war and peace, of justice and policy, which were debated in the councils of antiquity, will frequently present themselves as the subject of modern deliberation. But the most experienced statesman of Europe has never been summoned to consider the propriety or the danger of admitting or rejecting an innumerable multitude of barbarians, who are driven by despair and hunger to solicit a settlement on the territories of a civilised nation. When that important proposition, so essentially connected with the public safety, was referred to the ministers of Valens, they were perplexed and divided; but they soon acquiesced in the flattering sentiment which seemed the most favourable to the pride, the indolence, and the avarice of their sovereign. The slaves, who were decorated with the titles of praefects and generals, dissembled or disregarded the terrors of this national emigration—so extremely different from the partial and accidental colonies which had been received on the extreme limits of the empire.
http://www.ccel.org/g/gibbon/decline/volume1/chap26.htm#goth
Fusion-drummers, on the other hand, are really cute
https://www.youtube.com/watch?v=2C3Nml8IBf0
https://en.wikipedia.org/wiki/Classic_Maya_collapse#Drought_...
A civilizational collapse is rarely caused by a single event, but instead by multiple events - each which would be survivable on their own - causing a complete breakdown in the system. A society can survive a drought, a war, a plague, a famine, but all four at once might just be too much.
It's not for want of a nail that a kingdom is lost, but because of all accumulated failures and breakdowns which led to the point where loss of a single nail was just that one failure too much. Death by drowning in a million raindrops.
~ Glen Bowersock
The most important reason for the fall of Rome is frankly obvious, so obvious it's never mentioned: the severe political divisions within the Empire which caused it to fracture. The bulk of the intellectual and economic power in Rome shifted to the Eastern Empire, which lasted in its original form until the eighth century, and in some form until the fifteenth. The seeds of the fall of the Western Roman Empire in the fifth century were sown when Theodosius divided the Empire among his sons in 395, and there is hardly any comparable event today. There were various other reasons, of course; disease certainly didn't help, neither did the appearance of the Sassanids, the increasing irrelevance of the Senate, or famines in Gaul. But everyone on the right and the left wants Rome to have fallen because of its mishandling of their favorite political issue, be it inflation, military conscription, climate change, taxation, or as one amusingly inaccurate meme charges, religious intolerance. These accusations are all silly. The Roman Empire saw multiple civil wars between the reign of Constantine and the conquest by Odoacer. No developed country today faces such an issue. As soon as it was no longer able to draw support from the East, the Western Roman Empire began eighty years of monotonic decline.
If there is any moral to the story, it's that monarchy is unsustainable -- but we all knew that, anyway.
We may not see that today, but that was fairly common for Rome. Marius and Sulla's civil wars, Caesar's civil wars, and Octavian's civil wars all took place in a century. And chalking it all up to "monarchy is unstable" ignores the collapse of the Republic and the 4-15 centuries that the monarchy did pretty well.
As to whether the monarchic system was the reason Rome couldn't keep the whole Empire under one roof -- well, the Byzantines lasted, but they did so while controlling much less territory (Justinian's conquests were quickly lost), so while my argument is weak, I admit, your counterexample is also. The monarchy was successful from Octavian until Commodus; after that, it is hard to name two good rulers who succeeded each other, and impossible to name three. I think it is not by accident that during this early period the Senate was still politically relevant and vaguely democratic. But I am also just strongly tempted to blame regional divisions on poor governance, although there were probably other factors, and I am hardly a scholar.
>I think it is not by accident that during this early period the Senate was still politically relevant and vaguely democratic.
The senate had no actual power starting with Augustus, who turned it into a ceremonial institution. The only time it did have a shred of power was a succession crisis, and it maintained that power throughout.
>But I am also just strongly tempted to blame regional divisions on poor governance, although there were probably other factors,
I don't understand what you're saying here.
>The senate had no actual power starting with Augustus, who turned it into a ceremonial institution.
Early Emperors cared what the Senate thought, even if they didn't have to. Later ones didn't.
https://en.wikipedia.org/wiki/Roman_Senate#Senate_of_the_Rom...
>Around 300 AD, the emperor Diocletian enacted a series of constitutional reforms. In one such reform, he asserted the right of the emperor to take power without the theoretical consent of the senate, thus depriving the senate of its status as the ultimate depository of supreme power. Diocletian's reforms also ended whatever illusion had remained that the senate had independent legislative, judicial, or electoral powers. The senate did, however, retain its legislative powers over public games in Rome, and over the senatorial order.
Now we just know Glen was No True Historian.
Man I must've forgot to take my benzos today.
It's important in the sense that it investigates a typically neglected dimension, but I think historians will be hesitant to rank factors that led to the fall. Sufficiently self-aware historians are aware that the etiology of past events is a tricky business, and the best one can do is discuss a sequence of events with great detail that may or may not be linked by causation.
God our universities have rotted.
Sound familiar?
Too familiar
1. Everyone thinks they know why Rome fell
2. It never involves the state of the monetary policy in place
Quick bit of evidence, the Roman government pursued fast and loose debasement of their currency to prop up their heavy spending and terrible policies. Meaning, they were “printing too many coins” by diluting the amount of precious metal in each coin.
Emperors got loose printing money to support a heavy military spending to gain power and support from them. As seen in modern countries once hyper inflation hits, its game over.
Hyperinflation wasn’t game over for Germany. It had a brief empire shortly after it’s hyperinflation period.
I think its hard to find out which came first, but the moment the government started minting 99% gold coin (and they got away with it) -> 95% gold -> 90% gold till its a worthless "gold" coin too many bad things got put in motion.
I do agree its a confluence of factors. Maybe they expanded too much -> need more money -> print money -> cant exactly fire all the expeditionary forces -> print more money -> squeeze taxes out of populace -> people are getting fed up so output and tax revenues go down -> empire is too big -> attacks on Germany and Europe from the barbarians -> print more money to pay military -> squeeze people - > ad nauseum.
There's an established economic principle that "bad money drives out good". So while I do not think that just printing money is the only cause, once it occurs its down hill. You have to somehow figure out how you will try and reign it all in (thats what they tell themselves at least).
As to the Germany example, the hyper inflation can be fixed though who can really tell how traumatizing and painful it can be to those going through it. For sure it caused some discord and animosity and some people attribute it to the rise of Hitler and so forth.
My point generally is that historians should look at the entirety of factors and weigh them together. It is all too easy to point a quick finger at the military expansion, or climate or whatever and not combine them all. Very few places look at monetary theory probably because its relatively new (really with Friedman's work in middle 20th century), but also because it muddles the simplistic reason.
edit: clarity
On a more general level, empires as such are an unnaturally large and complex form of social organization, and for that reason they inevitably collapse at some point or another.