The Roman Empire experienced periods of stability and crisis over several centuries. In the 1st-2nd centuries AD, the Pax Romana brought peace and prosperity during the rule of emperors like Augustus and Trajan. However, the 3rd century saw a period of crisis as civil wars broke out among competing generals and Germanic tribes invaded. Diocletian and Constantine later restored stability in the 4th century. The Western Roman Empire eventually fell in 476 AD as Germanic tribes invaded and divided the territory into smaller kingdoms, while the Eastern Empire survived as the Byzantine Empire for another 1000 years.