[1][2] He is also mentioned in the accounts of Zacharias Rhetor, Evagrius Scholasticus, Jordanes, the Chronicon Paschale, Theophanes the Confessor and Joannes Zonaras.
[3] When Anastasius I (r. 491–518) died childless, without designating an heir, and without a reigning Augusta to supervise the election of a successor, the throne was up for grabs.
According to Malalas, the powerful praepositus sacri cubiculi Amantius had intended to elect a comes domesticorum, commander of an elite guard unit of the late Roman Empire, by the name of Theocritus to the throne.
[3][4] Amantius hoped to secure the election for Theocritus by bribing Justin, the comes excubitorum (head of the imperial guards).
The Excubitors then allegedly put forward Justinian, nephew of Justin, as their second candidate for the day, but he refused the crown.
The problem therefore was to manage that the initiation should proceed from the Senate, whose authority, supported by the excubitors, would rally general consent and overpower the resistance of the Scholarian guards.
Justin's friends in the Senate could argue with force: "Hasten to agree, or you will be forestalled, and some wholly unsuitable person will be thrust upon us.