The fall of Rome exerts a powerful hold on the popular imagination, but that’s not necessarily a good reason for academics to keep on writing about it.  No serious historian of the subject now thinks in terms either of purely internal or purely external causes for imperial collapse and, as I’m sure much of the audience has noticed, the list of factors discussed, even by historians coming to contradictory conclusions, tends to look pretty similar.  So why bother writing about it all again?  Might it be time to let the dust settle?

On the Roman side of the equation, I do more or less think so.  The last really new contribution here was the emergence of a quantatively huge body of archaeological evidence from the 1970s, which demonstrated that the late Empire on the eve of its disappearance was not – as everyone had thought up until about 1960 – an economic disaster area crumbling to dust.  And this perspective sits happily enough alongside plentiful historical evidence suggesting continued political and cultural vitality in the late imperial edifice.  But until something else radically new turns up, continued discussion of the internal Roman evidence is likely just to keep recycling now well-established points of view:  a clear sign in intellectual terms that it’s time to stop.  But the same is not yet true of the external factors.  Here, traditional academic subject divides still mean that a body of material that ought to be part of everyone’s understanding of Rome’s demise is often not discussed.  It also offers some alternative thoughts on what lessons we might draw from Rome’s collapse, other than the usual musings on wealth’s tendency to generate moral decay, or the savagery of foreigners.

At the start of the first millennium AD, as demonstrated by a vast body of archaeological evidence that has accumulated since the 1950s, its non-Mediterranean reaches were divided not so much into a two-speed as a three-speed Europe.  The southern and western largely Celtic-dominated territories were occupied by relatively dense populations with complex political and economic structures.  A second zone, in north-central Europe, was controlled by largely Germanic-speaking groups, and the third, north and east of the river Vistula, was home to, amongst others, Baltic- and Slavic-speakers.  The fundamental point, though, has nothing to with ethnicity, but the fact that zones two and three each represented steps away from the patterns of life visible in “Celtic” Europe.  Zone two had lower population densities, a simpler overall economy, and smaller-scale political structures than zone one, while population and complexity declined still further in zone three.  Move the clock forward a millennium, however, and the world had turned.  Right across zones two and three, powerful monarchies had emerged on the back of new agricultural technologies, which had vastly increased the amount of food available, and hence population densities, and rapidly intensifying economic structures.  Christianity was spreading fast, and the old zonal divides were rapidly becoming a thing of the past.

This astonishing transformation has many important historical resonances.  Not least, it marks the birth of Europe.  Europe is not a unit of physical geography – the so-called continent being merely western Eurasia – but product of human activity, and it was in this period that its human geography – demographic, political, economic, and cultural – first acquired sufficient similarities for their to be any point in thinking about Europe as an identifiable entity.  It also puts the whole Roman phenomenon into deeper perspective.

Rome was a Mediterranean-based Empire that used a highly-advanced war machine – originally developed to defeat Carthage – to conquer a wide range of adjacent territories, including most of Europe’s zone one.  This region was wealthy enough to be worth conquering, but not military or politically advanced enough to keep the legions in check.  Zone two, in whose fringes conquest petered out, simply wasn’t, around the birth of Christ, worth conquering.  Broader patterns of European development thus dictated the general extent of Rome’s northern conquests.

They also dictated Rome’s shelf-life.  Ecologically, the Mediterranean has limited but easily-worded agricultural assets, while sea links make communication between the patches of good land relatively quick.  That the Mediterranean should have seen early economic, political, and cultural development in many of its localities is not surprising. Nor is it surprising that competition between those localities, abetted by water-borne communications, should have been an intense process culminating in a single super-state. Non-Mediterranean Europe, by contrast, has vast agricultural resources, but they are much harder to work; its heavy soils required massive ploughs (characteristically eight animals to a team) to unlock their potential.  But once the necessary technology was available, northern population densities were bound to rise exponentially with knock-on effects for economic, political, and cultural complexity.  The new archaeological evidence – belonging to medieval and Slavic studies – shows this potential was slowly unlocked over the first millennium AD, providing an entirely new perspective on Rome’s fall.  A Mediterranean-based Empire could only dominate northern Europe when its own regional assets were relatively fully-developed and those of the north not.  Once the north’s mightier resources came online, the relationship was bound to reverse.  And from Charlemagne onwards (crowned Emperor on Christmas Day, 800), states with north European powerbases have dominated the Mediterranean, and not vice versa.

The history of Europe and the Mediterranean in longue durée contains, arguably, two more general lessons.  First, if political power is the result of precocious regional economic development, it cannot survive when other areas eventually catch up.  This may take more time, as with Rome and the north, or less time, as with the British imperial fluke based on early industrialization.  But sometimes, though politicians hate ever to admit it, holding on to pre-eminent power is not within the range of choice.  You can only choose the terms of its passing, like whether or not to wrack up huge debts maintaining military superiority in a new context.

Second, first-millennium development in central and eastern Europe was driven forward by processes analogous to modern globalization.  A series of new relationships – economic, political, and cultural – grew up between individuals and groups in the more-developed west and south and the less-developed east and north that, cumulatively and unintentionally, generated an astonishing revolution in Europe’s strategic balance of power.  And, like modern globalization, some of these relationships were beneficial to both parties, but others were not.  Indeed, one major stimulus to state formation in the first millennium was the desire to become powerful enough to fend off the worst excesses of imperialist intrusion.  The first millennium thus offers a second warning to the third.  Today’s junior trading partners will probably be tomorrow’s equals. The lesson to the United States:  be very careful exactly how you navigate your entirely unavoidable withdrawal from the status of pre-eminent power.