Emperor Maurice is not the best-known of characters. However, his overthrow and the years immediately afterward are a fascinating episode in the history of the Eastern Empire.
Not surprisingly his downfall was largely due to an army mutiny, when they were ordered beyond the Danube for winter.
Phocas was just a centurion, but he succeeded Maurice and soon displayed a vicious streak that sadly heralded an era of murder and mutilation in Byzantine history. (Only people who were ‘whole’ could become emperor, which meant a habit for blinding potential rivals arose). Initially welcomed by people sick of paying Maurice’s high taxes, he was not showered with universal affection after mutilating and killing the (former) imperial family.
The lands conquered by Beliasrius had been established into two Exarchates (semi-independent colonies) by Maurice, in Italy and Carthage. The latter of these began by ignoring Phocas’ claim to the throne, and then dispatching Heraclius and Nicetas (by sea and land respectively) to kick Phocas’ arse and take over. The Excubitor guards deserted Phocas upon Heraclius’ arrival, and Hercalius signalled his new reign by lopping off the head of his vile foe.
Heraclius may have a claim to be one of the unluckiest of emperors. He was tremendously competent in the field, and spent many years giving the Persians a damned good thrashing and reclaiming Byzantine territory. But history was against him.
The Persians were soon obliterated by the rise of Islam, and the Muslims took many of the lands Heraclius had previously conquered. Added to this, the emperor suffered intense pain due to disease. If that weren’t bad enough, the fact that he’d married his niece meant that many of his subjects weren’t particularly sympathetic and viewed his agony as divine retribution. Last but not least, just about all his descendents were rather inept emperors.
However, I do think Heraclius was a good emperor. Marrying his niece aside, he was competent and decisive, and won many victories in the field. He also reorganised civil and military structures to help alleviate the corruption that had set in under Phocas.