More recent historiography has tended to take a somewhat less categorical approach. The Western Empire did not so much fall as get transformed, it is not quite kosher to talk about a decline (but rises are always OK), certainly not the end of the civilisation and the Dark Ages is not a sensible term.
So it is refreshing to read a book by a serious historian and archaeologist saying, actually, no, the Western Empire was overrun by the barbarians, it was a very traumatic time, it was the end of a civilisation and what followed it was a period of decline and loss (particularly of literacy).
It is also reassuring that the picture we have been presenting to students in our Weapons and Armour presentation (1000 years of history in 50 minutes) is actually supported by the archaeological and other evidence.
The Fall of Rome: And the End of Civilisation is a short, clearly written book by Bryan Ward-Perkins, fellow of Trinity College, Oxford.
Ward-Perkins starts by outlining the shift in the dominant view about historians mentioned above. In Part One, he then goes through various written sources from the period to talk about the horrors of war as the Western empire is overrun and carved up into various Germanic kingdoms. He analyses the road to defeat (why the Western Empire fell and the Eastern Empire did not) as a result of the Western Empire having (due to simple geography) a harder task and poorer leadership. He notes that the Crisis of the Third Century showed that keeping the Empire functioning against a strong external challenge was no easy task. He then examines the Germanic takeover as being a genuine take-over, with the locals having a clearly inferior position.
In Part Two Ward-Perkins goes through the archaeological and other evidence about the level of comfort and sophstication that existed under the Empire (particularly as indicated by the widespread, standardised and high quality pottery) and the dramatic economic, cultural and population decline in the West in the C5th to C7th which has no parallel in the Eastern Empire until the wars of the C7th.
In Roman Britian, the decline upon the withdrawal of the legions is precipitous. The evidence (including such things as the average size of cows) is that the decline was to a lower level of technology and cultural sophistication than had existed in Iron Age Britain prior to the Roman conquest. He also points out that the "most backward" areas of the Western Empire (Wales, Brittany, Asturias) actually held out better. (I liked his comment that the last bit of the Western Empire to fall to the barbarians was when Wales was conquered by Edward Longshanks in 1282). This was because those areas had less economic specialisation so a more widespread level of basic skills in the population. The peace and common jurisdiction of the Empire allowed the building up of great networks of economic specialisation. This meant a high level of convenience and comfort, and not only for the elite. Once war and rapine disrupted that, the high level of specialisation became a high level of vulnerability. Pottery (and other production) becomes much less common and cruder, the population falls, literacy levels collapse. What follows was clearly worse than what had preceded it: a collapse from sophisticated complexity to survival-focused simplicity.
Ward-Perkins concludes with a (very polite) discussion of why current events (particularly the rise of the EU) had led to the creation of a historical view which nuances away overthrow, decline, conquest and collapse. I would go a bit further than Ward-Perkins does. After all, the traditional view meant that the Roman legions really were defending civilisation, and both the EU specifically--and contemporary academe in general--has a great dislike for the idea that thugs in uniform really can have a positive social role.
I found it a very sensible, very well-written and very enlightening book.