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 (symbasileis) 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 (25 December 800). 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 (Gr. Βασιλεύς), 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" (Gr. Αὐτοκράτωρ) 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 "[Emperor's name] in Christ, Emperor and Autocrat of the Romans" (cf. Ῥωμαῖοι and Rûm). 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)

{| class="wikitable" style="width:100%" ! style="width:10%" | Portrait ! style="width:15%" | Name ! style="width:13%" | Reign ! style="width:62%" | Notes (30 years, 9 months and 27 days) (24 years, 1 month and 25 days) (1 year, 7 months and 23 days)

Non-dynastic (363–364)

(7 months and 21 days)

Valentinianic dynasty (364–379)

(1 month and 2 days) (14 years, 4 months and 12 days) (5 months and 10 days)

Theodosian dynasty (379–457)

(15 years, 11 months and 29 days) (13 years, 3 months and 14 days) (42 years, 2 months and 27 days) (6 years, 5 months and 2 days)

Leonid dynasty (457–518)

(16 years, 11 months and 11 days) (10 months) (11 months and 11 days) August 476 – 9 April 491 (14 years and 8 months) (1 year and 7 months) (27 years, 2 months and 28 days)

Justinian dynasty (518–602)

(9 years and 23 days) (38 years, 7 months and 13 days) (12 years, 10 months and 21 days) (3 years, 10 months and 19 days) (20 years, 3 months and 14 days)

Non-dynastic (602–610)

(7 years, 10 months and 12 days)

Heraclian dynasty (610–695)

(30 years, 4 months and 6 days) (3 months and 14 days) (8 months and 25 days) (26 years and 10 months) (16 years and 10 months) (10 years)

Twenty Years' Anarchy (695–717)

(3 years) (7 years) (6 years, 2 months and 14 days) (1 year, 6 months and 30 days) (less than 2 years) (less than 2 years)

Isaurian dynasty (717–802)

(24 years, 2 months and 24 days) (34 years, 2 months and 27 days) (2 years and 5 months) (4 years, 11 months and 25 days) (16 years, 11 months and 11 days) (5 years, 2 months and 12 days)

Nikephorian dynasty (802–813)

(8 years, 8 months and 26 days) (2 months and 4 days) (1 year, 9 months and 9 days)

Non-dynastic (813–820)

(7 years, 5 months and 14 days)

Amorian dynasty (820–867)

(8 years, 9 months and 7 days) (12 years, 3 months and 18 days) (25 years, 8 months and 4 days)

Macedonian dynasty (867–1056)

(18 years, 11 months and 5 days) (25 years, 8 months and 12 days) (1 year and 26 days) (46 years, 5 months and 3 days) (24 years and 3 days) (3 years, 4 months and 6 days) (6 years, 3 months and 25 days) (6 years and 30 days) (49 years, 11 months and 5 days) (2 years, 10 months and 28 days) (5 years, 4 months and 30 days) (7 years, 7 months and 28 days) (4 months and 8 days) (1 month and 22 days) 12 June 1042 (1 month and 22 days) 11 January 1055 – 31 August 1056 (1 year, 7 months, 20 days) (12 years, 6 months and 30 days)

Non-dynastic (1056–1057)

"Stratiotikos" / "the Old"]] Μιχαὴλ Βρίγγας ὁ Στρατιωτικός/ὁ Γέρων (1 year and 8 days)

Komnenid dynasty (1057–1059)

(2 years, 2 months and 21 days)

Doukid dynasty (1059–1081)

(7 years and 6 months) (3 years and 9 months) (6 years, 5 months and 23 days) (2 years, 11 months and 29 days)

Komnenid dynasty (1081–1185)

(37 years, 4 months and 14 days) (24 years, 7 months and 24 days) (37 years, 5 months and 16 days) (3 years) (2 years)

Angelid dynasty (1185–1204)

(9 years, 6 months and 27 days) 1 August 1203 – 27 January 1204 (6 months and 8 days) (8 years, 3 months and 10 days) (6 months and 8 days) (2 months and 16 days)

Laskarid dynasty (Empire of Nicaea, 1204–1261)

(16 years and 6 months) (32 years and 11 months) (3 years, 9 months and 13 days) (3 years, 4 months and 9 days)

Palaiologan dynasty (restored to Constantinople, 1261–1453)

(23 years, 11 months and 10 days) (45 years, 5 months and 13 days) (26 years, 4 months and 21 days) (13 years and 22 days) (35 years, 1 month and 28 days) (7 years, 10 months and 2 days) (2 years, 10 months and 19 days) (10 years, 9 months and 13 days) (5 months and 3 days) (4 months and 30 days) (34 years, 4 months and 5 days) (23 years, 4 months and 10 days) (4 years, 4 months and 23 days)

Citations