How come Italy used to be the center of the civilized world,

[Alex Littleton]

Youre stupid the moors invaded sicily in the late 9th century idiot

[Plug Drugs]

since you're using wikipedia as the undisputed Word of Truth, i'll step it up a notch with some Yahoo! Answers

The collapse of central governing authority in the West meant that regional authorities were left to govern their various areas - most often military commanders, the strongest of whom were also immigrant barbarian federate kings. With no more central bureaucracy, Roman cities shrank or disappeared entirely and society reverted to a more "natural" rural agricultural base. Wealth was measured in land rather than money. There was also little role for learned civilian administrators outside of the church, so the landholding aristocracy focused on military service to maintain their status. The kings, in turn, tended to reward these loyal warriors with land.

Feudalism is often called the economic/social model that was typical for a medieval Europe. The foundation for a feudal economy were laid already during the late Roman Empire, and can be detected from the crisis of the 3rd century onward, and definitely from the Diocletian/Constantine economic reforms that changed the social and economic structure of the empire. The late Antiquity can be seen as time where the long distance trade disintegrated and the urban economy collapsed; so, citizens were leaving cities to move into landlord to obtain food and protection. This gave the basic foundation where people were giving up their personal citizenry and freedom from state to the latifundia landlord, who than were bestowing fiefdom titles to the land. People were forbidden under Diocletian reforms to switch trade, running from land, and their children were expected to follow the same path as their parents. This social immobility continued further fragmentation of the Roman Empire where provinces were left on its own and bound between them and Rome weakened.