Flavius Illus[1] (Ancient Greek: Ἴλλους or Ἰλλοῦς; died 488) was a Roman general who played an important role in the reigns of the Eastern Emperors Zeno and Basiliscus.
Illus served Zeno well, defeating the usurper Marcianus but came into conflict with the Dowager Empress Verina, and supported the revolt of Leontius.
Illus (Ancient Greek: Ἴλλους or Ἰλλοῦς)[2] was an Isaurian, but the time and place of his birth are unknown; he had a brother, called Trocundes.
[5] That persuaded Illus and Trocundes by the promises and gifts of Zeno to embrace his side and to march with united forces towards the capital.
Marcianus had married Leontia, daughter of the late Emperor Leo by Verina, and sister of Ariadne, Zeno's wife.
The brothers escaped, but Marcianus was sent, either to Tarsus in Cilicia, and made a priest in the church there, or to the foot of Papurius, or Papyrius, a stronghold in Isauria, then used as a state prison.
Pamprepius was a native of Thebes, or, according to others, of Panopolis in Egypt, an avowed heathen, and eminent as a poet, a grammarian, and especially for his skill in divining the future.
Zeno was prone to jealousy and so it is not surprising that the commanding position and popular favour of Illus rendered him an object of suspicion and that the emperor in various ways sought to rid himself of him.
He went first to Nicaea and then, on pretence of change of air to cure his wound, to the East, where he was made general of all the armies with the power of appointing the provincial officers.
Illus declared Leontius emperor, defeated the army of Zeno near Antioch, and, having drawn over the Isaurians to his party and captured Papurius, released Verina, and induced her to crown Leontius at Tarsus and send a circular letter to the imperial officers at Antioch, Egypt, and the East by which they were prevailed upon to join Illus.
Illus and Leontius were ignorant of his fate, and, encouraged by Pamprepius who gave them assurances of Trocundes's return and of ultimate victory, held out with great tenacity for over three years.