The expansion of Roman power throughout the Mediterranean affected many aspects of political life.
Conquests meant enslavement of many conquered people, thus expanding the role of slavery in the Roman economy and contributing to the growth of large estates (latifundia) and possibly to economic inequality as well.
Roman became far richer by her conquests, acquiring most importantly a secure grain supply from the enormously fertile Nile region of Egypt.
Rome’s conquest of Greece by force of arms led to an influx of Greek culture into Rome, transforming Roman literature, rhetoric, and art to reflect Greek models.
The expansion of the Roman empire led to the Pax Romana, a 200-year period of relative peace that followed the consolidation of Roman power. The Romans ruled what was at that time an enormous empire of 70 million people. They built a system of roads throughout their lands and established a strong military presence in their territories. This allowed people to travel long distances safely and thus led to a growth in commerce and cultural exchange. It also led to Rome accumulating vast wealth. Not only did the Romans borrow heavily from Greek culture, which they greatly admired, they were able to support learning, a leisure class, and the arts throughout the empire and to build or appropriate vast libraries. At the time of its final fall, the Roman empire was so intellectually advanced that it would take more than a 1,000 years for Europe to begin to surpass it.
The Pax Romana eased the spread of Christianity because of the relative safety of travel in the empire, as well as the use of Greek as a common language. Even as the empire came under increasing threat, at which point Christianity was adopted by Emperor Constantine, the vast learning in the empire allowed Constantine to assemble the best minds in the world to hash out a sophisticated Christian theology in various councils, such as the Nicene. This had an influence within the empire and thereafter. Gibbon, who wrote The Decline and Fall of the Roman Empire, contended that the cultural impact of Christianity undermined the empire.
The impact of the expanded empire has been vigorously debated, but some scholars contend that it led to high income inequality and debt peonage to a point that these factors undermined the empire and weakened it from within.