In the years following Justinian's death, the empire was rocked from within and without. Barbarians pushed in on every border and the empire's ancient enemy Persia ravaged the East unchecked. The empire met this challenge with a series of weak and foolish rulers who squandered what resources they had, and crumbled before the Persian onslaught. By the start of the 7th Century, the emperor was a virtual prisoner in his own palace, the Persians were beneath the walls of Constantinople, and the rest of the empire was in the hands of rebels. It looked as if the end had come at last, and yet, against all odds, an Armenian general was to defeat the Persians, sweep away the old Latin traditions and reform the empire on a Greek model. Join Lars Brownworth as he looks at Heraclius, whose reign saw this glittering triumph yet ended in such tragedy.