The Romans never foresaw the collapse of their empire. St. Augustine of Hippo blamed it on paganism. Italian Renaissance poet Petrarch claimed that internal factors caused the empire’s demise, while political theorist Machiavelli credited “barbarians” with Rome’s destruction. Enlightenment thinker Edward Gibbon wrote in his Decline and Fall of the Roman Empire that Roman excess and the rise of Christianity contributed to the empire’s end by weakening Rome’s military tradition.

As Germanic groups at Rome’s western frontiers became agriculturalists, their populations grew, pushing them into Roman lands. At times, thousands of outsiders flooded into Roman territories together; they also entered as newly-recruited soldiers to the Roman army or as laborers seeking work. Surviving writings such as those attributed to the Roman poet Ausonius indicate that Romans conceived of a “static world” in the fourth century (21). His poetry also shows that paganism was already in decay by the time Christianity eclipsed it: “[…] the gods were shadows of their formerly lively selves” (22).

Over time, the middle class vanished, and powerful elites controlled most land during the Roman Empire’s twilight. Lesser landholders became “tenants” of overlords, who created the basis for medieval Europe’s fiefs. Germanic elites came to dominate some of these lands and “became lords of a kind, extending protection in return for labor and produce” (27).