I just read Adrian Goldsworthy’s How Rome Fell, which is about how Rome fell.  Apparently it’s become a little controversial to say that it did… new studies emphasize the continuity of daily life and institutions and like to talk about “transformation”.  Goldsworthy take the reasonable position that this revisionism has gone too far: Rome’s decline really was a disaster, though a long drawn-out one.

Historians can have these debates at all because there’s so much that we just don’t know about Rome.  We have no economic statistics, so we can’t really say what happened to living standards.  We can’t say what the size of the army was, or what government revenues were, or what size the cities were, or how big the Germanic tribes were.  There are periods for which we have good histories and some where we barely know what was going on.  Archeology helps, but by its nature it’s anecdotal… we can look at particular sites or shipwrecks, but hardly have a picture of the whole empire.

Still, it’s pretty clear that between 200 and 600, western Roman urban civilization collapsed.  Wide-scale trade dried up; cities grew smaller or were abandoned; living standards declined; Roman engineeering was lost.  Europe in 600 was less populated, more rural, poorer, ravaged.  The main caveat is that this process was slow, and particular events such as the fall of Romulus Augustulus in 476 were just landmarks along the way, not sudden catastrophes.  People didn’t forget from one day to the next how to build a watermill or maintain a standing army.  But over the whole period, these skills were indeed lost.

Why did it happen?  Goldsworthy isn’t bold enough to reduce it to a paragraph or two, but I am: the Romans never got the hang of monarchy, and mostly destroyed themselves in civil war.  The height of the empire was the period of the “Five Good Emperors” from Nerva to Marcus Aurelius, from 96 to 180; each emperor was carefully chosen and adopted by the previous one.  It’s not hard to blame Marcus Aurelius for spoiling the pattern by choosing his own son Commodus, who proved to be corrupt and arrogant.  A state can survive one or two such nincompoops, but not a succession of them… see also the later Yuan rulers of China.

The real trouble started later, however– from 217 to the end of the Western empire, there was rarely a period as long as a decade without a civil war.  Many emperors were usurpers, and none got through his reign without facing internal challengers.  Civil wars devastated the country, sapped and corrupted the soldiers, reduced troop strength along the frontiers, and impelled emperors to isolation and paranoia.  The barbarian invasions didn’t show an increased foreign threat so much as the loss of the ability to address it. 

(Some Tea Partiers who fantasize about a coup d’etat would do well to learn this lesson.  Want to destroy America?  That’s the royal road.)

Rome both needed and feared a large standing army.   In its heyday the army was probably hundreds of thousands strong; but armies were increasingly localized, and vitiated by the civil wars and the difficulty of payment.  Emperors learned not to allow rivals access to large forces; but that meant that the entire empire could no longer be run by just one man.  By the late 400s no one in the west could maintain even a few tens of thousands as a standing army– Justinian’s reconquests in the west were won with forces well under 15,000 men.

People love to compare Rome to the current contemporary superpower, but from this and other accounts, the region most similar to the late Western Empire is Africa– a region where power is easily seized by force, where leaders can be completely crazy,  and where officials are so thoroughly, hopelessly corrupt that ‘normal’ economic development is impossible.  (‘Normal’ is in scare quotes because arguably the typical case in history is precisely that endemic corruption, not those fortunate times and periods with honest governments and honest businessmen.)