Final answer:
The question explores a tumultuous period in Roman history where external threats and internal instability led to significant challenges for the empire, including territorial losses and political upheaval.
Step-by-step explanation:
The question pertains to a period in Roman history when the empire faced numerous threats from external forces like the Goths, Huns, and Persians, as well as internal political turbulence. Noteworthy events include the capture of Emperor Valerian by the Persians, the Roman settlement of the Goths that led to their uprising and later sacking of Rome, and the Roman emperors' military campaigns against invading barbarians and the Persians.Empire defense strategies included fee payment to the invaders, such as the annual tribute paid by Emperor Justinian to the Persians, and military reforms attempted by various emperors. The decline in Roman leadership and the empire's weakening grasp on its territories led to a number of generals, including Romanos IV and Pompey the Great, playing decisive roles in defending and expanding the empire's borders.In conclusion, a combination of external pressures and internal instability during this era of Roman history ultimately weakened the empire, resulting in lost battles, territory, and significant political changes.