Those agencies could not carry out their mission of enforcing regulations
Conventions are meeting that delegates have one famous convention is the constitutional convention. And if your talking about the fun conventions like the science ones or beauty conventions those are like party anyone is invited to
Invasions of people--many of the groups came as military and fought the Romans as invading forces.
Counterclaim--they were migration patterns as they were attempting to gain access to an empire with advanced trade and education. Migrating to the Roman Empire gave a person or group with extra resources.