Justinian II, known as Rhinotmetus (the Split-nosed) (669-711) was Byzantine emperor from 685 to 695 and again from 704 to 711. He succeeded his father, Constantine IV, at the age of sixteen.

His reign was unhappy both at home and abroad. After a successful invasion he made a truce with the Arabs, granting them joint possession of Armenia, Iberia and Cyprus. By removing 12,000 Christian Maronites from their native Lebanon, he gave the Arabs command over Asia Minor, leading to their conquest of Armenia in 692.

In 688 Justinian decisively defeated the Bulgars. Meanwhile the bitter dissensions caused in the Church by the emperor's bloody persecution of the Manichaeans, and the rapacity with which (through his creatures Stephanus and Theodatus) he extorted the means of gratifying his sumptuous tastes and his mania for erecting costly buildings, drove his subjects into rebellion.

In 695 they rose under Leontius and, after cutting off the emperor's nose (whence his surname), banished him to Cherson in the Crimea. Leontius, after a reign of three years, was in turn dethroned and imprisoned by Tiberius Absimarus, who next assumed the purple.

Justinian escaped from Cherson after almost nine years and married Theodora, sister of Ibousiros Gliabanos (Busir Glavan), khagan of the Khazars. They were given a home in the town of Phanagoria . Busir was offered a bribe by Tiberius to kill his brother in law, and dispatched two Khazar officials, Papatzys and Balgitzin, to do the deed. Warned by his wife, Justinian fled the town, but not before murdering Papatzys and Balgatzin.

Justinian next fled to Terbelis (Terval), khan of the Danube Bulgars (see Bulgaria). Terval offered his support in exchange for financial considerations and the award of a caesar's crown. With an army of 15,000 Bulgar horsemen Justinian pounced upon Constantinople. Unable to take the city by force, he and some companions entered through an unused aquaduct, roused their supporters, and seized control of the city in a midnight coup d'etat. Justinian then had his rivals Leontius and Tiberius along with thousands of their partisans executed, and once more ascended the throne in 704.

His second reign was marked by an unsuccessful war against the Bulgars under Terval, Arab victories in Asia Minor, devastating expeditions sent against his own cities of Ravenna and Cherson where he inflicted horrible punishment upon the disaffected nobles and refugees, and the same cruel rapacity toward his subjects. Justinian met Pope Constantine I and the two negotiated a settlement.

Justinian's tyrannical rule provoked another rising against him. Cherson revolted; under the leadership of Bardanes, the city held out against a counter-attack and soon the forces sent to suppress the rebellion joined it. The rebels then seized the capital and proclaimed Bardanes as emperor; Justinian was forced to flee and was assassinated in Asia Minor in December 711. He was the last of the house of Heraclius.

A fictional account of Justinian's life is given in the 1998 novel Justinian by H.N. Turteltaub.