Basiliscus (Latin: Flavius Basiliscus Augustus; Greek: Βασιλίσκος) (d. 476/477) was Byzantine Emperor from 475 to 476. A member of the House of Leo, he came to power when Emperor Zeno had been forced out of Constantinople by a revolt.
Basiliscus was the brother of Empress Aelia Verina, who was the wife of Emperor Leo I (457–474). His relationship with the Emperor allowed him to pursue a military career that, after minor initial successes, ended in 468, when he led the disastrous Roman invasion of Vandal Africa, in one of the largest military operations of Late Antiquity.
Basiliscus succeeded in seizing power in 475, exploiting the unpopularity of Emperor Zeno, the "barbarian" successor to Leo, and a plot organised by Verina that had caused Zeno to flee Constantinople. However, during his short rule, Basiliscus alienated the fundamental support of the Church and the people of Constantinople, promoting the Miaphysite christological position in opposition to the Chalcedonian faith. Also, his policy of securing his power through the appointment of loyal men to key roles antagonised many important figures in the imperial court, including his sister Verina. So, when Zeno tried to regain his empire, he found virtually no opposition, triumphantly entering Constantinople, and capturing and killing Basiliscus and his family.
Basiliscus was the only son of the East Roman (Byzantine) military commander Armatus and briefly Caesar of the East Roman Empire in 476–477/8. In later life, he became a priest and finally bishop of Cyzicus.
Basiliscus' father Armatus played a crucial role in helping Emperor Zeno (r. 474–491) reclaim Constantinople from the usurper Basiliscus (whom Armatus had initially helped in his own rise to power) in 476. In exchange, Zeno crowned Armatus's son, still a boy, as Caesar, effectively marking him out as his heir. It is possible that the young Basiliscus adopted the regnal name of Leo at this occasion, but this is disputed.
Soon after, however, in 477 or 478, Armatus fell from imperial favour and was executed. Basiliscus was spared the same fate through the intervention of the Empress Ariadne, but was forced to become a cleric. Initially he became a lector at Blachernae, and eventually he rose to become bishop of Cyzicus. He possibly survived as late as the reign of Justinian I (r. 527–565).
Basiliscus is a genus of large corytophanid lizards, commonly known as basilisks, which are endemic to southern Mexico, Central America, and northern South America. They are commonly known as the Jesus Christ Lizard, or simply the Jesus Lizard, due to their ability to run across water for significant distances before sinking.
Both the generic name, Basiliscus, and the common name, "basilisk", derive from the Greek basilískos (βασιλίσκος) meaning "little king". The specific epithet, vittatus, which is Latin for "striped", was given in Carl Linnaeus' 10th edition of Systema Naturae.
The basilisk has blue spots and a yellow iris, on average measures 70 to 75 mm (2.8–3.0 in), and weighs about 80 grams (3.2 oz). Its growth is perpetual, fast when they are young and nonlinear for mature basilisks. Its long crest-like sails, reinforced in three distinct points (head, back, and tail), confer the impression of creatures such as Dimetrodon and Edaphosaurus. Its skin is shed in pieces.