Letting Germanic Tribes in Roman Borders -
Germanic tribes outside of Rome had less and less territory as Rome began to expand more, and then finally they were pushed again by the Huns. They fled to Rome for safety, and the Romans let them into their borders. The Romans, however, treated these tribes very poorly, and this led to lots of conflict and eventually to tribes such as the Goths and Vandals to sack Rome.
The decline of the Roman trade routes was mainly caused by the constant warfare between the Romans and the Germanic tribes, as well as the fact that these tribes constantly pillaged and destroyed things such as trade routes, farms etc.
