Flavius Arbitio (

fl. ''Floruit'' (; abbreviated fl. or occasionally flor.; from Latin for "they flourished") denotes a date or period during which a person was known to have been alive or active. In English, the unabbreviated word may also be used as a noun indicatin ...

354–366 AD) was a Roman general and Consul who lived in the middle of the 4th century AD.

In the Reign of Constantius II

Arbitio was a general of

Constantine I Constantine I ( , ; la, Flavius Valerius Constantinus, ; ; 27 February 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337, the first one to convert to Christianity. Born in Naissus, Dacia Mediterrane ...

. Under Constantius II, the son and successor of Constantine, he became magister equitum (commander of the cavalry). Arbitio was a well trusted courtier of Constantius, and some modern historians have suggested he was his military strongman. In 355 he was made

consul Consul (abbrev. ''cos.''; Latin plural ''consules'') was the title of one of the two chief magistrates of the Roman Republic, and subsequently also an important title under the Roman Empire. The title was used in other European city-states throug ...

together with Quintus Flavius Maesius Egnatius Lollianus. Arbitio intrigued against

Claudius Silvanus Silvanus (died 7 September 355) was a Ancient Rome, Roman general of Franks, Frankish descent, Roman usurper, usurper in Gaul against Emperor Constantius II for 28 days in AD 355. Origin and career Silvanus was born in Gaul, the son of Bonitus ...

, Ursicinus and

Barbatio Barbatio (died AD 359) was a Roman general of the infantry (Magister Peditum = Master of Foot) under the command of Constantius II. Previously he was a commander of the household troops (''protectores domestici'') under Gallus Caesar, but he arres ...

and played a role in their downfalls. Historian

Ammianus Marcellinus Ammianus Marcellinus (occasionally anglicised as Ammian) (born , died 400) was a Roman soldier and historian who wrote the penultimate major historical account surviving from antiquity (preceding Procopius). His work, known as the ''Res Gestae ...

says he was "keen and eager in plotting treachery", and describes him as "fickle flatterer" to Constantius II.

In the Reign of Julian

After the death of Constantius in 361, he was appointed chairman of the

Chalcedon tribunal Shortly after the death of Roman emperor Constantius II, his successor Julian held a tribunal at the city of Chalcedon, which was then a suburb of Constantinople. Saturninius Secundus Salutius, who was raised to the rank of Praetorian Prefect was ...

by the new Emperor Julian. In this function he was responsible for the conviction of

Paulus Catena Paulus Catena ('the Chain' or 'the Fetter') (''fl.'' 350s, d. 361/2) was a senior Roman public official who served as an investigator and notary for Constantius II during the mid- fourth century.Seeck 1906, p. 233 He is principally known through th ...

and many ministers and followers of Constantius. Arbitio did not take part in the Persian campaign of Julian, but instead retired to live as a private citizen.

In the Reign of Valens

A couple of years after Julian's death, a maternal relative of Julian named

Procopius Procopius of Caesarea ( grc-gre, Προκόπιος ὁ Καισαρεύς ''Prokópios ho Kaisareús''; la, Procopius Caesariensis; – after 565) was a prominent late antique Greek scholar from Caesarea Maritima. Accompanying the Roman gener ...

made an attempt to usurp the Eastern Empire. Arbitio himself was courted by this Procopius. However, Arbitio ignored the summons of Procopius, who, in response, confiscated his properties. This action led Arbitio to join Procopius' opponent,

Valens Valens ( grc-gre, Ουάλης, Ouálēs; 328 – 9 August 378) was Roman emperor from 364 to 378. Following a largely unremarkable military career, he was named co-emperor by his elder brother Valentinian I, who gave him the eastern half of ...

, who appointed Arbitio "ad hoc ''magister militum''". During the subsequent campaign, Arbitio was able to convince Gomoarius, a general in the army of Procopius and an old friend of Arbitio, to desert to Valens. Eventually, Procopius was deserted by most of his troops, and attempted to hide from his fate, but was tied up by two of his attendants and turned over to Valens, who had both the usurper and his betrayers executed.Ammianus Marcellinus, 26.9.9 What happened to Arbitio after this time is unknown, although it is reasonable to assume that he retired, and subsequently died without taking any further part in matters of state.

Footnotes

Sources

, Loeb Classical Library * Lenski, N.E., ''Failure of empire: Valens and the Roman State in the fourth century A.D. (2002) {{end 4th-century Gallo-Roman people Ancient Roman generals Generals of Constantine the Great Generals of Constantius II Generals of Valens Imperial Roman consuls Magistri equitum (Roman Empire)