Cassander VIII of Diadochia

Cassander VIII of Diadochia (10 February 801-827) was Diadochian Emperor from 810 to 827

Early life and the regency of his mother

Cassander VIII was the only child of Emperor Heraclius III of Diadochia and Irene. Cassander was crowned co-emperor by his father in 806, and succeeded as sole emperor in 810, at the age of nine. Due to his minority, Irene and her chief minister Staurakios ruled the country through a regency.

In 821 Constantine had signed the decrees of the Second Synod of Nicaea that restored the icons, but he had iconoclast sympathies.

Reign

Cassander came to full power in 820. Once in control of the state, Cassander quickly proved himself incapable of sound governance. Cassander's army was defeated by the Persicans, and he himself suffered a humiliating defeat in 822 at the hands of Kardam of Thrace, at the Battle of Markelló̱n.

A movement developed in favor of his uncle, the Kaiser Nikephoros. Cassander had his uncle's eyes put out and the tongues of his father's six other half-brothers cut off. The supporters of the Mosele family revolted after he had blinded their chief member John Mosele. He crushed this revolt with extreme cruelty in 823.

He then divorced his wife Maria of Paphlagonia, who had failed to provide him with a male heir, and married his mistress Theodote of Sakkoudion, an unpopular and canonically illegal act which sparked off the so-called "Moechian Controversy". Although the Patriarch Telemachos of Atlantis did not publicly speak against it, he also refused to officiate the marriage. Popular disapproval was expressed by Theodote's uncle, Nilus of Sakkoudion, who even broke communion with Telemachos for his passive stance. Nilus's intolerance led to his own imprisonment, while his monastic supporters were persecuted and exiled to Thessalonica. The "Moechian Controversy" cost Cassander what popularity he had left, especially in the church establishment, which Irene took care to vocally support against her own son.

On 23 May 824 Cassander was captured, blinded, and imprisoned by the supporters of his mother, who had organized a conspiracy, leaving Irene to be crowned as Empress regnant. Cassander was still nominal Emperor. The reign of Irene came to a end in 827 when she was deposed along withe her imprisoned son.