How much of an impact did the Roman emperors' civil wars have on their decision to debase the coinage?

Question

From Adrian Goldsworthy's How Rome Fell: "Civil war remained a common event, ...the economy collapsed, as successive emperors massively devalued the coinage to pay for their wars."

Other sources say the emperors debased the coinage to pay soldiers for wars for the empire (i.e., not for their own civil wars): "This income was not enough, however, to cover the entire cost of the new army [made in response to the new Persian threat], and in the late third century emperors also pursued two further strategies. First, they debased the coinage..." (The Fall of the Roman Empire by Peter Heather)

So did the emperors debase the coinage for their own civil wars, or for wars against external enemies?

"By 268 there was only 0.5 percent silver in the denarius." (mises.org/daily/3663 - transcript of Professor Joseph Peden's lecture)

Did such huge debasement occur as a result of the emperors' need to fund troops for their civil wars, or for foreign wars? It seems that it was likely a combination of both, but which played a bigger part in causing the coinage to eventually be reduced to less than 1% silver content?

If it is hard to say, are there any examples (hopefully more than a few, and at least fairly significant) of certain emperors debasing the coinage mainly due to their civil war?

Answer 1

Look into the "Crisis of the Third Century." You'll note that the date given in the Perden lecture is towards the end of this period.

The best answer is probably "both" and "neither."

During the ~ 50 years of the Crisis Rome had 26 Emperors: most of them were generals who established their rule through force. Thus your answer is civil war.

But while the various Emperors killed each other, they neglected the borders, and raids from Sassinads, Goths, Vandals, etc were frequent. The Emperors then needed even more troops to defend the borders. Thus your answer is war for empire.

But the reality is the two are related to each other. Foreign powers raided the Empire because they believed they could get away with it: the Empire appeared divided and distracted. But if an Emperor cannot protect his people from outside forces, he loses the respect of his people and his soldiers, and the likelihood of a coup increases.

So the two effects re-enforce each other - internal discord leads to external attacks leads to internal discord. A simple answer - such as '[Civil or Foreign] Wars forced the Emperors to devalue the currency' is almost certain to be incomplete.

Answer 2

Nobody knows for sure since there was no annual budget or even centralized government accounting.

However, it seems that the necessity to pay soldiers in the context of usurpation and civil wars was the deciding factor. During the late IInd century, it had become standard practice to pay a bonus to (loyal) troops on the accession of a new emperor; the so-called donativum. Initially, these payments were relatively modest and also quite infrequent as the regins were relatively long. But as the pace of usurpation started to pick up, these bonuses became nearly yearly events and the amounts also went up as usurpers tried to outbid each other.

In my view, the practice of the donativum and the endless civil wars were part of the process which nearly drove the Roman Empire into the ground: the transformation of the Principate into a Military Dictatorship gone mad. With every general in the Empire being a potential emperor, but also at the same time a potential victim of summary execution within the next 6 months if he chose the wrong side, it is a small wonder that financial discipline collapsed entirely.