At its height in the second century A.D., the Roman Empire was the beacon of learning, trade, power and prosperity in the western world. But success eventually spoils. That Empire–rotten to the core by the fifth century–lay open to barbarian warriors who came in wave after wave of invasion–slaughtering, stealing, and ultimately, settling. As chaos replaced culture, Europe was beset by famine, plague, persecutions, and a state of war that was so persistent it was only rarely interrupted by peace.