The Fall Of The Roman Empire

Continuing on my history track, after the decline of the Roman Empire, came its fall.

The decline of Rome was the natural and inevitable effect of immoderate greatness.

Prosperity ripened the principle of decay; the cause of the destruction multiplied with

the extent of conquest; and, as soon as time or accident had removed the artificial

supports, the stupendous fabric yielded to the pressure of its own weight.

The story of the ruin is simple and obvious; and instead of inquiring why the Roman Empire

was destroyed, we should rather be surprised that it had subsisted so long.

~Edward Gibbon (1737-1794)

477 CE. The highlighted portions are the parts that survived the deposition of the Last Roman Emperor, Romulus Augustus, by Odoacer (the first kind of Italy).
Source: Wikipedia

And on that sober note, here are some theories that have been put forth about Rome's fall:

1. Climate Change:  it's global cooling!  The drying and cooling climate destroyed ancient agriculture, causing famine.
2. Soil Exhaustion:  all the lands around the Mediterranean had been depleted of their nutrients and could no longer sustain the intensive agriculture to support the Empire's population (and troops).
3. Lead Poisoning:  Romans were great architects, but perhaps not great at chemistry, for they used lead in all their pipes (including those bringing their water), which led to widespread lead poisoning and sterility.
4. Racial Pollution:  too many immigrants!  It must be because of all those Syrians', Greek's and Jews' seed that destroyed Roman vitality and made them unable to rule anymore! (Wow, I had not idea this had been an actual theory.  Then again, people at one point thought the Earth was flat...)
5. Slavery:  Romans depended too much on their slaves so they got too fat and lazy to defend themselves.
6. Intellectual Stagnation:  no advance in science and technology = economic dead end.
7. Social Disorder:  the middle class was destroyed by civil war (in the third century CE, Emperors even encouraged the poor to plunder the middle class!), invasion, over taxation (this sounds familiar, doesn't it?) which had been, until then, the most productive and culturally aware part of the Roman population.
8. Excessive government:  too many governmental exactions and regulations destroyed the market economy which was their basis for prosperity (this one sounds familiar too).
9. Christianity:  adopting Christianity as the official state religion in the fourth century CE meant a weak Roman Empire that diverted its scarce resources to building churches and monasteries, and meant larger portions of the population were pacifists.
10. Immorality:  the old Roman virtues that had allowed what had once been a small village to turn into a thriving and powerful empire disappeared to be replaced by gluttony, sloth and sexual depravity.

So there you have it.  It's interesting, isn't it, how there can be so many different views on what may or may not have happened a couple millennia ago?

An interesting graph on the devaluation of the Roman coin, showing the (hyper) inflation the Roman population felt towards the Empire's end.

Reference:

The Heritage of World Civilizations