Q: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
What was the largest spreading belief after the fall of Rome?, Context: With the fall of the Western Roman Empire, there arose a more diffuse arena for political studies. The rise of monotheism and, particularly for the Western tradition, Christianity, brought to light a new space for politics and political action[citation needed]. During the Middle Ages, the study of politics was widespread in the churches and courts. Works such as Augustine of Hippo's The City of God synthesized current philosophies and political traditions with those of Christianity, redefining the borders between what was religious and what was political. Most of the political questions surrounding the relationship between Church and State were clarified and contested in this period.
A:
Christianity