Professor Freedman introduces the major themes of the course: the crisis of the Roman Empire, the rise of Christianity, the threats from barbarian invasions, and the continuity of the Byzantine Empire. At the beginning of the period covered in this course, the Roman Empire was centered politically, logistically, and culturally on the Mediterranean Sea. Remarkable for its size and longevity, the Empire was further marked by its tolerance. Although it contained an eclectic mix of peoples, the Empire was unified in part by a local elite with a shared language and customs. In the third century these strengths were increasingly threatened by the Empire’s sheer size, its imbalances, both East-West and urban-rural, and by an army that realizes it could make and unmake emperors. Having set the scene, Professor Freedman looks to subsequent lectures where he will discuss reforms enacted to address these weaknesses.