List of Byzantine emperors

The foundation of Constantinople in 330 AD marks the conventional start of the Eastern Roman Empire, which fell to the Ottoman Empire in 1453 AD. Only the emperors who were recognized as legitimate rulers and exercised sovereign authority are included, to the exclusion of junior co-emperors who never attained the status of sole or senior ruler, as well as of the various usurpers or rebels who claimed the imperial title.
The following list starts with Constantine the Great, the first Christian emperor, who rebuilt the city of Byzantium as an imperial capital, Constantinople, and who was regarded by the later emperors as the model ruler. Modern historians distinguish this later phase of the Roman Empire as Byzantine due to the imperial seat moving from Rome to Byzantium, the Empire's integration of Christianity, and the predominance of Greek instead of Latin.
The Byzantine Empire was the direct legal continuation of the eastern half of the Roman Empire following the division of the Roman Empire in 395. Emperors listed below up to Theodosius I in 395 were sole or joint rulers of the entire Roman Empire. The Western Roman Empire continued until 476. Byzantine emperors considered themselves to be Roman emperors in direct succession from Augustus; the term "Byzantine" became convention in Western historiography in the 19th century. The use of the title "Roman Emperor" by those ruling from Constantinople was not contested until after the papal coronation of the Frankish Charlemagne as Holy Roman emperor.
The title of all emperors preceding Heraclius was officially "Augustus", although other titles such as Dominus were also used. Their names were preceded by Imperator Caesar and followed by Augustus. Following Heraclius, the title commonly became the Greek Basileus, which had formerly meant sovereign, though Augustus continued to be used in a reduced capacity. Following the establishment of the rival Holy Roman Empire in Western Europe, the title "Autokrator" was increasingly used. In later centuries, the emperor could be referred to by Western Christians as the "emperor of the Greeks". Towards the end of the Empire, the standard imperial formula of the Byzantine ruler was " in Christ, Emperor and Autocrat of the Romans".
Dynasties were a common tradition and structure for rulers and government systems in the Medieval period. The principle or formal requirement for hereditary succession was not a part of the Empire's governance; hereditary succession was a custom and tradition, carried on as habit and benefited from some sense of legitimacy, but not as a "rule" or inviolable requirement for office at the time.

Constantinian dynasty (306–363)

Valentinianic dynasty (364–392)

Theodosian dynasty (379–457)

Leonid dynasty (457–518)

Portrait	Name	Reign	Notes
	Leo I "the Thracian"	7 February 457 – 18 January 474	Born in Dacia 400, and of Bessian origin, Leo became a low-ranking officer and served as an attendant of the Gothic magister militum, Aspar, who chose him as emperor on Marcian's death. He was the first emperor to be crowned by the Patriarch of Constantinople, and the first one to legislate in Greek. His reign was marked by the pacification of the Danube and peace with Persia, which allowed him to intervene in the affairs of the West, supporting candidates for the throne and dispatching an expedition to recover Carthage from the Vandals in 468. Initially a puppet of Aspar, Leo began promoting the Isaurians as a counterweight to Aspar's Goths, marrying his daughter Ariadne to the Isaurian leader Tarasicodissa. With their support, in 471 Aspar was murdered and Gothic power over the army was broken.
	Leo II "the Younger"	18 January – November 474	Born 468, he was the grandson of Leo I by Leo's daughter Ariadne and her Isaurian husband, Zeno. He was raised to Augustus on 17 November 473. Leo ascended the throne after the death of his grandfather on 18 January 474. He crowned his father as co-emperor and effective regent on 29 January, dying shortly after.
	Zeno	29 January 474 – 9 January 475	Born 425 in Isauria, originally named Tarasicodissa. As the leader of Leo I's Isaurian soldiers, he rose to comes domesticorum, married the emperor's daughter Ariadne and took the name Zeno, and played a crucial role in the elimination of Aspar and his Goths. He was named co-emperor by his son on 29 January 474 and became sole ruler upon the latter's death, but had to flee to his native country before Basiliscus in 475, regaining control of the capital in 476. Zeno concluded peace with the Vandals, saw off challenges against him by Illus and Verina, and secured peace in the Balkans by enticing the Ostrogoths under Theodoric the Great to migrate to Italy where the Gothic king ruled. Convincing Theodoric to move his Goths westward into Italy allowed Zeno to reduce what had been a drain to imperial resources, since these Germanic warriors had been exacting payments from the Empire throughout the 470s and 480s and menacing Eastern territories. As a consequence, Zeno's reign also saw the end of the western line of emperors. His pro-Miaphysite stance made him unpopular and his promulgation of the Henotikon resulted in the Acacian Schism with the papacy.
	Basiliscus	9 January 475 – August 476	General and brother-in-law of Leo I, seized power from Zeno and crowned himself emperor on 12 January. Zeno was restored soon after. Died in 476/477
	Zeno	August 476 – 9 April 491	Retook the throne with the help of general Illus. Saw the end of the Western Roman Empire. Died of dysentery or epilepsy
	Anastasius I "Dicorus"	11 April 491 – 9 July 518	Born 430 at Dyrrhachium, Anastasius was a palace official when he was chosen as the husband and ultimately Emperor by Empress-dowager Ariadne. He was nicknamed "Dikoros", because of his heterochromia. Apparently, there was some insistence from the citizenry of Constantinople that Zeno's successor should be an "Orthodox" Christian, which caused Ariadne to turn to Anastasius in the first place. Anastasius reformed the tax system and the Byzantine coinage and proved a frugal ruler, so that by the end of his reign he left a substantial surplus. His Miaphysitism led to widespread opposition, most notably the Revolt of Vitalian and the Acacian Schism. His reign was also marked by the first Bulgar raids into the Balkans and by a war with Persia over the foundation of Dara. He died childless. Shortly before his death, he tried to devise a means for one of his three nephews to succeed him by placing a note that read Regnum under their beds, but when none of them chose that bed, he decided instead to name the first person he saw the following morning. Keeping true to his word, when Justin—commander of the imperial guards—entered his presence first that morning, he was pronounced as Anastasius's successor.

Justinian dynasty (518–602)

Heraclian dynasty (610–695)

Portrait	Name	Reign	Notes
	Heraclius	5 October 610 – 11 February 641	Born as the eldest son of the Exarch of Africa, Heraclius the Elder. Began a revolt against Phocas in 609 and deposed him in October 610. Brought the Byzantine-Sassanid War of 602–628 to successful conclusion but was unable to stop the Muslim conquest of Syria. Heraclius' officials worked to replace Latin with Greek as the official language of administration in the East. By this time Latin had long fallen out of everyday use in the Eastern part of the Empire and Heraclius's adopting of the title basileus "marked a shift from Rome towards a Greek and Eastern Christian culture."
	Heraclius Constantine	11 February – 25 May 641	Born on 3 May 612 as the eldest son of Heraclius by his first wife Fabia Eudokia. Named co-emperor on 22 January 613, he succeeded to throne with his younger brother Heraklonas following the death of Heraclius. Died of tuberculosis, allegedly poisoned by Empress-dowager Martina.
	Heraclonas	25 May – 5 November 641	Born in 626 to Heraclius' second wife Martina, named co-emperor on 4 July 638. Succeeded to throne with Constantine III following the death of Heraclius. Sole emperor after the death of Constantine III, under the regency of Martina, but was forced to name Constans II co-emperor by the army, and was deposed by the Senate in September 641.
	Constans II "the Bearded"	September 641 – 15 July 668	Born on 7 November 630, Constans II was the son of Constantine III. Raised to co-emperor in summer 641 after his father's death due to army pressure, he became sole emperor after the forced abdication of his uncle Heracleonas and his exile. Baptized Heraclius, he reigned as Constantin but was given the nickname "Constans". He faced a number of Arab incursions, almost losing his life while commanding the Byzantine fleet. Constans had some military success against the Slavs in the Balkans. Around 662, he moved his seat and court to Syracuse, intending to liberate Italy from the Lombards. His presence was unwelcome in Italy and there was "fierce opposition" to Constans II's abandonment of Constantinople. He was assassinated by a chamberlain in 668.
	Constantine IV "the Younger"	September 668 – 10 July 685	Born in 652, co-emperor since 13 April 654, he succeeded following the murder of his father Constans II. Erroneously called "Constantine the Bearded" by historians through confusion with his father. He called the Third Council of Constantinople which condemned the heresy of Monothelitism, repelled the First Arab Siege of Constantinople, and died of dysentery.
	Justinian II "Rhinotmetus"	July 685 – 695	Born in 669, son of Constantine IV, he was named co-emperor in 681 and became sole emperor upon Constantine IV's death. Deposed by military revolt in 695, mutilated and exiled to Cherson, whence he recovered his throne in 705.