Basil Onomagoulos was a Byzantine

Byzantine

Byzantine usually refers to the Roman Empire during the Middle Ages.Byzantine may also refer to:* A citizen of the Byzantine Empire, or native Greek during the Middle Ages...

 official who was declared rival emperor 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,...

 in 717, taking the regnal name Tiberius.

Basil was from 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:...

, the son of a certain Gregory Onomagoulos. In 717 he was a member of the entourage of Sergius, the Byzantine governor of 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,...

, when news arrived to the island of the fall of Constantinople, the Byzantine imperial capital, to an Arab siege. At this point Sergius declared Basil as emperor, taking the name Tiberius. The Emperor Leo III the Isaurian

Leo III the Isaurian

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

 (r. 717–741) however quickly dispatched a chartoularios

Chartoularios

The chartoularios or chartularius , Anglicized as chartulary, was a late Roman and Byzantine administrative official, entrusted with administrative and fiscal duties, either as a subaltern official of a department or province or at the head of various independent bureaus.-History:The title derives...

named Paul, whom he named patrikios and strategos

Strategos

Strategos, plural strategoi, is used in Greek to mean "general". In the Hellenistic and Byzantine Empires the term was also used to describe a military governor...

of Sicily, with a few men and imperial instructions for the army. On his arrival, the people of Syracuse and the army surrendered the rebels. Basil and his head general were beheaded and their heads sent to the emperor, while the other rebels were tonsure

Tonsure

Tonsure is the traditional practice of Christian churches of cutting or shaving the hair from the scalp of clerics, monastics, and, in the Eastern Orthodox Church, all baptized members...

d or mutilated

Political mutilation in Byzantine culture

Mutilation in the Byzantine Empire was a common method of punishment for criminals of the era but it also had a role in the Empire's political life. The mutilation of political rivals by the Emperor was deemed an effective way of sidelining from the line of succession a person who was seen as a...

 and exiled. Sergius himself managed to escape to the Lombards

Lombards

The Lombards , also referred to as Longobards, were a Germanic tribe of Scandinavian origin, who from 568 to 774 ruled a Kingdom in Italy...

in mainland Italy, and returned only after he received guarantees that no harm would befall him.

Sources