Final answer:
The subject of this question is History, and it relates to an individual who ruled as co-Emperor with his father in the Western Roman Empire, winning victories and putting down revolts.
Step-by-step explanation:
The subject of this question is History. The question refers to an individual who ruled as co-Emperor with his father, Valerian, over the Western Roman Empire while his father ruled the East. He won many victories in modern-day Germany and put down multiple revolts by his generals in regions of the empire.This individual is commonly associated with the decline and fall of the Western Roman Empire, a significant event in ancient history.