Final answer:
The question addresses a historical figure who was a son and co-Emperor with Gordian and died in Carthage, yet the information provided discusses various Roman emperors and the complexities of imperial succession, highlighting important figures such as Commodus and Marcus Aurelius.
Step-by-step explanation:
The question refers to the historical period of Roman Imperial succession, a turbulent time marked by a series of emperors who faced various challenges. The son and co-Emperor with Gordian, who died in battle in Carthage, faced a well-trained force as described, but unfortunately, the context provided does not align well with historic details about Gordian's life.
The context provided discusses Roman Emperors such as Commodus, who was known for his arrogance and foolhardiness, and his succession after Marcus Aurelius; the turbulent Crisis of the Third Century with rapid changes in leadership; and the unsuccessful process of hereditary succession after great rulers like Augustus and Alexander the Great.
Commodus' reign, as well as that of many other emperors, exemplifies the challenges of succession and governance in the ancient Roman Empire, especially when the practice of choosing competent leaders ended. It highlights the complexities of hereditary succession versus the appointment of successors based on merit, and the political instability that can arise when an incapable ruler takes the throne.