21 Historical Photos That Might Change Your Perspective On Things

The empire had split into East and West, further breaking down a sense of unity, and Christianity was replacing the Roman polytheistic religion. When you become a student of history, you learn how to process facts like these and consider how one event affected the other. An expanding empire is harder to control, and invasions further tax resources. But what caused that instability in the first place? And why did expansion remain so important?