Final answer:
The century following the end of the Pax Romana saw the Roman Empire grappling with the Crisis of the Third Century, characterized by frequent changes in leadership, economic strife, cultural shifts, and the rise of Christianity. Despite these challenges, the legacy of Roman civilization persisted well beyond the empire's political decline.
Step-by-step explanation:
Following the end of the Pax Romana, the century that ensued was marked by significant challenges and transformations within the Roman Empire. The Pax Romana had been a period of relative peace and prosperity initiated by Emperor Augustus, lasting approximately 200 years, until the death of Marcus Aurelius. After this, the Roman Empire entered a phase historically known as the 'Crisis of the Third Century', characterized by drastic political instability, economic troubles, and external threats.
Roman governance was plagued by rapid turnover of emperors and continuous civil wars. The economic instability was further exacerbated by currency devaluation, leading to rising prices for goods. This period also saw the gradual eastward shift of the Empire's cultural center of gravity, a prelude to the establishment of Byzantium and Late Antiquity sightings, a time that straddles the ancient and medieval worlds.
Christianity started to gain a foothold during these tumultuous times, spreading across the Empire and ultimately becoming a dominant religion. Despite challenges including leadership instability and threats from the Sasanians and various Germanic kingdoms, Roman civilization left an enduring legacy that continued to influence Western Civilization during and after the Late Roman Empire through to the end of the western half of the Empire in 476 CE.