or in the middle of the rule of a dynasty, it is customary among historians to group them together with the rulers of said dynasty, an approach that is followed in this list. Dynastic breaks with non-dynastic rulers are indicated with thickened horizontal lines. Principate (27 BC – AD 284) Julio-Claudian dynasty (27 BC – AD 68) Year of the Four Emperors (68–69) Flavian dynasty (69–96) Nerva–Antonine dynasty (96–192) Year of the Five Emperors (193) Note: The other claimants during the Year of the Five Emperors were Pescennius Niger and Clodius Albinus, generally regarded as usurpers. Severan dynasty (193–235) Crisis of the Third Century (235–285) Dominate (284–476) Tetrarchy (284–324) Constantinian dynasty (306–363) Valentinianic dynasty (364–392) Theodosian dynasty (379–457) Last western emperors (455–476) Later eastern emperors (457–1453) Leonid dynasty (457–518) Justinian dynasty (518–602) Heraclian dynasty (610–695) Twenty Years' Anarchy (695–717) Isaurian dynasty (717–802) Nikephorian dynasty (802–813) Amorian dynasty (820–867) Macedonian dynasty (867–1056) Doukas dynasty (1059–1078) Komnenos dynasty (1081–1185) Angelos dynasty (1185–1204) Laskaris dynasty (1205–1261) Note: Roman rule in Constantinople was interrupted with the capture of the city by the Fourth Crusade in 1204. Though the crusaders created a new line of Latin emperors in the city, modern historians recognize the line of emperors of the Laskaris dynasty, reigning in Nicaea, as the legitimate Roman emperors during this period as the Nicene Empire eventually retook Constantinople. For other lines of claimant emperors, see List of Trapezuntine emperors and List of Thessalonian emperors. Palaiologos dynasty (1259–1453) See also List of Roman and Byzantine empresses – for the consorts of the emperors List of Roman usurpers – for a list of unsuccessful claimants to the position of emperor (41–470) List of Byzantine usurpers – for a list of unsuccessful claimants to the position of emperor (479–1448) List of Roman dynasties – for a list of the many dynasties that ruled the Roman Empire List of Roman consuls – for a list of the consuls who held power during the Roman Republic and who continued to be appointed in imperial times List of Roman dictators – for a list of dictators during the Roman Republic Family tree of Roman emperors – for a concise family tree of emperors and their immediate family (27 BC–518 AD) Family tree of Byzantine emperors – for a concise family tree of emperors and their immediate family (337–1453) Notes References Citations Main bibliography Secondary bibliography External links "The Rulers of