Heraclius sailed from Carthage to Constantinople, deposed and executed Phocas, and took the throne at a moment of grave crisis, with Persian armies advancing on the empire's eastern provinces. His reign would see catastrophic early losses followed by a stunning counter-offensive that crushed the Sassanid Persian Empire, though it left Byzantium exhausted just before the rise of Islam.
Heraclius arrived in Constantinople in 610 to find an empire in near collapse. Phocas, who had seized power eight years earlier through a bloody mutiny, had proven a brutal and incompetent ruler, and the Persian Sassanid Empire was tearing through Byzantine territory in the east virtually unopposed. Heraclius had Phocas dragged before him, reportedly demanding to know why he had ruled so badly, before having him executed.
The early years of his reign were disastrous — Jerusalem fell to the Persians in 614, and the True Cross itself was carried off as a trophy, a spiritual catastrophe for Christendom. Egypt and much of Anatolia followed.
Yet Heraclius engineered one of history's great reversals, personally leading campaigns deep into Persian territory through the 620s, eventually forcing a Persian collapse and recovering the True Cross in 630. The victory came at ruinous cost: both empires were so drained that within a decade Arab armies, newly unified under Islam, swept through and permanently seized Byzantium's richest eastern provinces.
Key people: Heraclius, Phocas