Flavius Illus (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 supported the revolt of Basiliscus against Zeno and switched sides to support the return of Zeno (475–476). Illus served Zeno well, defeating the usurper Marcianus but came into conflict with the Dowager Empress Verina, and supported the revolt of Leontius. The rebellion failed, and Illus was killed.
Flavius Appalius Illus Trocundes (Greek: Τρόκονδος, died 485) was a general of the Eastern Roman Empire, involved in the rise and fall of Emperor Basiliscus and the rebellion against Emperor Zeno.
Trocundes was the brother of Illus, another Roman general. Both of them were from the region of Isauria.
Flavius Marcianus (Greek: Μαρκιανός, fl. AD 469–484) was a member of the Leonid dynasty. The son of the Western emperor Anthemius, Marcianus married Leontia, the daughter of the Eastern Roman emperor Leo I. He was consul twice, and in 479 unsuccessfully attempted to overthrow the emperor Zeno. After his capture he was forced to become a monk; he escaped and raised an army but was defeated and recaptured by Flavius Appalius Illus Trocundes. In 484, when the Isaurian general Illus revolted against Zeno, Marcianus was freed and Illus proclaimed him emperor, before deposing him in favour of Leontius.
Basiliscus (Ancient Greek: Βασιλίσκος, romanized: Basilískos; died 476/477) was Eastern Roman emperor from 9 January 475 to August 476. He became magister militum per Thracias in 464, under his brother-in-law, Emperor Leo I (r. 457–474). Basiliscus commanded the army for an invasion of the Vandal Kingdom in 468, which was defeated at the Battle of Cape Bon. There were accusations at the time that Basiliscus was bribed by Aspar, the magister militum; many historians dismiss this, instead concluding that Basiliscus was either incompetent or foolish for accepting Vandal King Gaiseric's offer of a truce, which the latter used to construct fireships. Basiliscus's defeat cost the Eastern Empire 130,000 pounds (59,000 kg) of gold, causing the empire to hover above bankruptcy for 30 years. When Basiliscus returned to Constantinople, he sought refuge in the Hagia Sophia. His sister, Empress Verina, secured him a pardon and he left the church to retire in Neapolis.
When Emperor Leo died in 474, his grandson Leo II (r. 474) took power, but soon died; his father, Zeno (r. 474–475, 476–491) ascended the throne in the same year, in a politically precarious position. Verina conspired to install the magister officiorum Patricius, her lover, as emperor. This plot was supported by Basiliscus, who succeeded in recruiting Isaurian brothers Illus and Trocundes, as well as Verina's nephew Armatus. Zeno fled on 9 January 475, either after learning of the plot or after Verina warned him that his life was in danger. Although Patricius was Verina's intended successor, Basiliscus convinced the Eastern Roman Senate to acclaim him instead.