Documentary series about the Roman Empire. Three-part series retraces the last 400 years of the Empire, from its zenith to the first wave of barbarian invasions, and examines the possible reason that, after conquering the whole of the Mediterranean and achieving unprecedented dominance over its subject peoples, the Empire collapsed like a house of cards. The Roman Empire takes an investigative approach, assessing the positive and negative aspects of Roman civilization. The Roman handed down and built on Greek learning and founded wonderful cities around the Mediterranean. But Roman society was riddled with corruption and power-struggles, and the vast spread of the Empire made it vulnerable. In the third century AD, when it was at its greatest, the Roman Empire became engaged in a struggle for its very survival.