What factors led to the collapse of the Western Roman Empire?

Answer 1

You should read, in its entirety, Edward Gibbons' monumental "History of the Decline and Fall of the Roman Empire."
http://www.worldcat.org/oclc/1526725

Or, if you're too lazy, you could take a look at:
http://ancienthistory.about.com/cs/romefallarticles/a/fallofrome.htm

Answer 2

With the death of Stilicho in 408, Honorius was left in charge, and although he ruled until his death in 423, his reign was filled with usurpations and invasions, particularly by the Vandals and Visigoths. In 410, Rome was sacked by outside forces for the first time since the Gallic invasions of the 4th century BC. The instability caused by usurpers throughout the Western Empire helped these tribes in their conquests, and in the 5th century the Germanic tribes became usurpers themselves. In 475, Orestes, a former secretary of Attila the Hun drove Emperor Julius Nepos out of Ravenna and proclaimed his own son Romulus Augustus as emperor.

Although some isolated pockets of Roman rule continued (in north-western Gaul under Syagrius and Britannia, with Ambrosius Aurelianus), the control of Rome over the West had effectively ended. In 476, Orestes refused to grant the Heruli led by Odoacer federated status, and Odoacer sacked Rome and sent the imperial insignia to Constantinople, installing himself as king over Italy.




The Western and Eastern Roman Empires by 476History regards that the Western Roman Empire ended on 4 September 476, as Odoacer deposed Romulus Augustus. However, the issue is a bit more complicated and unclear.

Julius Nepos still ruled in the rump state of Dalmatia, claiming sovereignty over the Western Roman Empire and was recognized as such by Byzantine Emperor Zeno and by Syagrius, who had managed to preserve a Roman exclave in Gaul, known today as the Domain of Soissons. Odoacer proclaimed himself ruler of Italy and began to negotiate with the Byzantine emperor. Zeno eventually did acknowledge Odoacer's position as patrician of the Roman Empire and accepted him as his own viceroy of Italy, but he insisted that Odoacer acknowledge Nepos formally as western emperor. Odoacer did so and even issued coins in Nepos' name throughout Italy. It was mainly an empty political gesture because Odoacer never returned any real power or territories to "his emperor". Nepos was eventually murdered in 480 and Odoacer quickly invaded and conquered Dalmatia.

A similar situation occurred in northern Gaul where the Roman general Syagrius minted coins in Nepos' name until his own defeat in 486. Nevertheless, Julius Nepos was mostly ignored, and Romulus Augustulus entered into history as the Last (Western) Roman Emper

Answer 3

There are theories as to why this may have happened..........here's mine: I believe there was too much internal strife. Too much crisis as to who should lead and make major decisions. This caused division and open the gates to manipulation and greed.