What were some reasons for decline of the Roman Empire?

First of all, when the empire moved its capital to constantinople, it basically left Rome and the western half of its provinces to its own devices, in that it was too far from the seat of power to rule effectively. Also, it's my personal belief that Christianity helped bring down the empire. I mean this is an empire that was in power for a few centuries before the birth of Christ. When Constantine became a Christian, (thereby setting the example) it had to wreck some havoc, as this religion was COMPLETELY different from their old religion which was sponsored by the state. Before Christianity, when Rome conquered a place, they set up administration and tax collectors,etc. but never forced anyone to accept their religion - as Roman religion was for Romans and noone else. Which is very different from Christianity, as it is tenet of that religion to "spread the word".

The Roman Empire was already decedent and too big to govern before the rise of Constantine, and there was always a threat of barbarians, although you could say that these problems became more prominent.

It could so be as simple as the fact that the empire was OLD by the time of the fall, and could not keep up with changing times.

there are a few reasons actually as some have mentioned it was the division of the empire and the political sqabbling that comes with this ,also rome relied heavily on other lands for its wealth and as mentioned by ither answers it had got to big and needed even more wealth to sustain its birders but thus it was not possible with the backstabbing between the two leaders of the empires east and west to expand and the infighting led to poor defences and back door deals with those who seek power ,the one thing that did survve was the roman catholic church it was seen by the smart power keeping romans as away to control and hang on to power although a different empire an empire non the less

-----The Roman Empire lasted as long as it did because of its great civil service that kept everything running well. It declined because by definition the civil service could only follow orders; it could not make fundamental changes as needed to meet new conditions as they arose. Only the rulers--decision makers--could do that and they did not, or did not do a good job. By the way, the first thing I was taught about the Holly Roman Empire in school was that it was not holly, not Roman, and not an empire. -----Jim

it was on a leaning and splippery surface.

Seriously:

- longtime economical stasis in West roman empire (wealthier Eastern empire, then known as Byzantium Empire, lasted until -1453 AD)

- decay in defense force

- cultural division (Latin language was devided in many dialects since 4th century AD)

-Barbaric invasions.

Eventually, some barbarian chieftain efforded more stability and protection to peoplethan the dying Roman Empire (they founded in western europe so said Roman-Barbaric Kingdoms: Visigotians, ecc.)

There was constant barbarian invasion, civil war, and runaway hyperinflation.

by the most official time of the sacking of Rome the Eastern empire was significantly richer.

http://en.wikipedia.org/wiki/Roman_empire

It was too large for them to control all of it from Rome. The Barbarians they could have easily conquered but did not because the people became lazy and gave into all sorts of stuff I can't talk about. And lastly bad inbred leadership.

There were many reasons, but I guess a few would be that it got too large to effectively protect and govern, "barbarian" invasions, and lead in the drinking water.

Something I saw was boredom.

People doing the same things pointlessly ad nauseum. The same territories, the same politicians, the same taxes, the same enemies--their names may have changed but they all came from the same direction to do the same things. The dream was gone, the fire was gone, the ambition was gone, the means were gone.

Bottom line is they got too greedy, they exacted loyalty & ruled harshly, and they became decadent. Oh wait, are we talking about the American Empire here? ;-)

Just some nice videos to watch:

Bu$h and his men fooled the RELIGIOUS

http://youtube.com/watch?v=fbC3_VCNvnU&mode=relate...

Keith Olbermann deconstructs Bill O'Reilly

http://youtube.com/watch?v=FfSRwUxjmM4&mode=relate...

Patriot Fact: Duke Cunningham

http://www.youtube.com/watch?v=Zsc7u7bgPu4&mode=re...

Patriot Fact: Porter Goss

http://www.youtube.com/watch?v=9jWWi7i6754&NR

We Have Too Many Stink'n Rights!

http://www.youtube.com/watch?v=OGY-53BzAB8&mode=re...

they were being invaded a lot be the vikings and when the Emperor Charlamange died his sons sons split up the empire into three parts and then it just kinda fell apart.