Mezezius was an Armenian noble who served as a general of Byzantium

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

, later usurping the Byzantine throne in Sicily

Sicily

Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

 from 668

668

Year 668 was a leap year starting on Saturday of the Julian calendar. The denomination 668 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Childeric II succeeds Clotaire III as King...

 to 669

669

Year 669 was a common year starting on Monday of the Julian calendar. The denomination 669 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Deaths :* December 31 – Li Shiji, Chinese...

.

According to a letter from Pope Gregory II to Emperor Leo III

Leo III the Isaurian

Leo III the Isaurian or the Syrian , was Byzantine emperor from 717 until his death in 741...

, he was Count of the Opsikion

Opsikion

The Opsician Theme or simply Opsikion was a Byzantine theme located in northwestern Asia Minor . Created from the imperial retinue army, the Opsikion was the largest and most prestigious of the early themes, being located closest to Constantinople...

, the imperial retinue , and a later Syriac chronicle describes him as a patrikios. After Constans' murder at the baths of Daphne in 668, he was proclaimed emperor by the army thereafter and reigned in Sicily for a few months; however, when the news of the assassination of Constans reached his son Constantine IV

Constantine IV

Constantine IV , , sometimes incorrectly called Pogonatos, "the Bearded", by confusion with his father; was Byzantine emperor from 668 to 685...

 in Constantinople

Constantinople

Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

, an expedition was sent to depose and kill him. His court was deported to Constantinople.