Rulers of the Roman Empire and the Roman Republic

Updated August 5, 2020 | Logan Chamberlain

Over a millennium of leadership (good and bad)

Take me to the Kings | Take me to the Republic Leaders | Take me to the Emperors

More than a millennium passed between the founding of Rome and the collapse of the Western Roman government in 476. The span of Ancient Roman history saw some of the ancient world's most important (and bizarre) characters. Read on to learn about the leaders of the Rome and their remarkable lives.

The Kingdom

The city of Rome was founded in 753 BC. According to the (mythologized) histories passed down by Roman historians, the city-state was ruled by seven kings who held almost absolute power. The kings began with Romulus, brother of Remus and son of Mars, and end with the tyrant Tarquinius in 509. Tarquinius, the story goes, was a criminal of the worst sort, setting off a legendary series of events that led to the ousting of the king and the founding of the republican government.

The Republic

The Roman Republic was the successor to the kingdom of Rome. It carried over a lot of the same traditions, and even some of the same government bodies like the Roman Senate. The government of the Republic can take a bit of explaining as it's quite complicated. To keep things simple, we've just listed the most influential leaders of the Republic, their titles, and their lifespan. 

The Empire

The Roman Empire began during the rule of the first Roman emperor, Augustus, after he won the civil war against Mark Antony and CleopatraPeople often mistakenly believe that Julius Caesar was the first emperor, but he was only ever named dictator for life. Part of the confusion might come from the fact that many emperors would style themselves after Caesar and after Augustus; Trajan, for example, was officially Imperator Caesar Nerva Traianus Augustus. 

The Roman emperors are typically divided by dynasty. But, with all of the assassinations and coups and civil wars, there are a lot of gaps between dynasties. There are also other traditional divisions. The first five emperors of the Nerva-Antonine dynasty, for example, are typically known as the Five Good Emperors.  We've done our best to separate out these different groups.For the Emperors we've just listed the dates of their reign.

Kingdom of Rome

Roman Republic

Roman Empire

  • The Julio-Claudian Dynasty

    • Augustus, (Octavian) first emperor, grandnephew of Julius Caesar, (27 B.C.–A.D. 14)
    • Tiberius, stepson of Augustus, (14–37)
    • Caligula, grandnephew of Tiberius (37–41)
    • Claudius, uncle of Caligula (41–54)
    • Nero, stepson of Claudius (54–68)
  • The Year of the Four Emperors

    • Galba, proclaimed emperor by his soldiers (68–69)
    • Otho, military commander (69)
    • Vitellius, military commander (69)
    • Vespasian, military commander (69–79)
  • The Flavian Dynasty 

    • Vespasian, military commander (69–79)
    • Titus, son of Vespasian (79–81)
    • Domitian, son of Vespasian (81–96)
  • The Nerva-Antonine Dynasty

    • The Five Good Emperors
    • Lucius Verus, adopted by Antoninus Pius; ruled jointly with Marcus Aurelius (161–169)
    • Commodus, son of Marcus Aurelius (180–192)
  • Pertinax, proclaimed emperor by the Praetorian Guard (193)
  • Didius Julianus, bought office from the Praetorian Guard (193)
  • The Severan Dynasty

    • Septimius Severus, proclaimed emperor (193–211)
    • Caracalla, son of Severus (211–217)
    • Geta, son of Severus, ruled jointly with Caracalla (211–212)
    • Macrinus, proclaimed emperor by his soldiers (217–18)
    • Heliogabalus or Elagabalus, cousin of Caracalla (218–222)
    • Alexander Severus, cousin of Heliogabalus (222–235)
  • Maximin, proclaimed emperor by soldiers, (235–238)
  • The Gordian Dynasty

    • Gordian I, made emperor by the senate (238)
    • Gordian II, son of Gordian I, ruled jointly with his father (238)
    • Balbinus, elected joint emperor by the senate (238)
    • Pupienus Maximus, elected joint emperor with Balbinus by the senate (238)
    • Gordian III, son of Gordian II (238–244)
  • Philip (the Arabian), assassin of Gordian III (244–249)
  • The Decian Dynasty

    • Decius, proclaimed emperor by the soldiers (249–2251)
    • Hostilianus, son of Decius, colleague of Gallus (251)
    • Gallus, military commander (251–253)
    • Aemilianus, military commander (253)
  • The Valerian Dynasty 

    • Valerian, military commander (253–260)
    • Gallienus, son of Valerian, coemperor with his father and later sole emperor (253–268)
    • Claudius II, military commander (268–270)
    • Aurelian, chosen by Claudius II as successor (270–275)
    • Tacitus, chosen by the senate (275–276)
    • Florianus, half brother of Tacitus (276)
    • Probus, military commander (276–282)
  • The Caran Dynasty 

    • Carus, proclaimed by the Praetorian Guard (282–283)
    • Carinus, son of Carus (283–285)
    • Numerianus, son of Carus, joint emperor with Carinus (283–284)
  • Diocletian, military commander, divided the empire; ruled jointly with Maximian and Constantius I 284–305)
  • Maximian, appointed joint emperor by Diocletian (286–305)
  • The Constantinian Dynasty 

    • Constantius I, joint emperor and successor of Diocletian (305–306)
    • Galerius, joint emperor with Constantius I (305–310)
    • Maximin, nephew of Galerius (308–313)
    • Licinius, appointed emperor in the West by Galerius; later emperor in the East (308–324)
    • Maxentius, son of Maximian (306–312)
    • Constantine I (the Great), son of Constantius I (306–337) and first emperor to convert to Christianity
    • Constantine II, son of Constantine I (337–340)
    • Constans, son of Constantine I (337–350)
    • Constantius II, son of Constantine I (337–361)
    • Magnentius, usurped Constans' throne, (350–353)
    • Julian (the Apostate), nephew of Constantine I (361–363)
  • Jovian, elected by the army (363–364)
  • The Valentinian Dynasty

    • Valentinian I, proclaimed by the army; ruled in the West (364–375)
    • Valens, brother of Valentinian I; ruled in the East (364–378)
    • Gratian, son of Valentinian I; coruler in the West with Valentinian II (375–383)
    • Maximus, usurper in the West (383–388)
    • Valentinian II, son of Valentinian I, ruler of the West (375–392)
  • Eugenius, usurper in the West (393–394)
  • The Theodosian Dynasty

    • Theodosius I (the Great), appointed ruler of the East (379–395) by Gratian; last ruler of united empire (394–395)
    • Emperors in the West
      • Honorius, son of Theodosius (395–423)
      • Maximus, usurper in Spain (409–411)
      • Constantius III, named joint emperor by Honorius (421)
      • Valentinian III, nephew of Honorius and son of Constantius III (425–455)
    • Emperors in the East
  • Emperors in the West

    • Petronius Maximus, bought office by bribery (455)
    • Avitus, placed in office by Goths (455–456)
    • Majorian, puppet emperor of Ricimer (457–461)
    • Libius Severus, puppet emperor of Ricimer (461–465)
    • Anthemius, appointed by Ricimer and Leo I (467–472)
    • Olybrius, appointed by Ricimer (472–473)
    • Glycerius, appointed by Leo I (473–474)
    • Julius Nepos, appointed by Leo I (474–475)
    • Romulus Augustulus, put in office by Orestes, his father (474–476)
  • Emperors in the East

    • Leo I, chosen by the senate (457–474)
    • Leo II, grandson of Leo I (474)
    • Zeno (474–475)
    • Basilicus (475–476)

For more Roman biographies, check out our encyclopedia.

About the Republic and the Empire

The government of the Republic changed a lot over time, but it always involved the same three basic groups. First was the Senate, who acted as advisers and represented the nation. The Senate was made up of esteemed members of the public. Senators were typically from prominent families or were formerly elected members of the government.

Next to the Senate were the magistrates. The magistrates were government officials elected by the citizens of Rome, both the upper class patricians and the lower class plebeians. The two highest ranked magistrates were the consuls, the supreme co-rulers of Rome who commanded the Roman army. Other important magistrates included the censors, who took the census and selected the senators. In times of crisis, this normal system could be overridden by appointing a dictator who would have total authority.

Lastly, there were the assemblies. Roman citizens would assemble vote on electing officials, enacting laws, and declaring war. Importantly, citizenship wasn't extended to all people under Roman rule, or even all Romans on the Italian peninsula. Citizenship was inherited from parents, or was offered to people by the government. The assemblies were assisted by the Tribunes, who were able to intervene on behalf of the plebeians as a safeguard against the senate and magistrates. 

Over time, the assemblies became less and less influential. Power fluctuated within the Senate. By the end of the Republic, Roman generals, dictators, or the Senate itself chose the senators, and political power concentrated itself into fewer hands. 

The Principate

The early era of the Roman Empire is often called the Principate. The Principate was ruled by a single emperor known as the princeps. During the Principate, the emperors at least kept up the image of being a republic. The Senate continued to hold some political importance, and the Emperor was called princeps to indicate that he was merely the "first among equals"--the elected consuls were still officially the heads of state in the empire. That was, of course, a lie. At best, consuls could be promoted to important administrative roles. 

The Dominate

The later era of the Roman Empire, when it was divided into the Eastern and Western Roman Empires, is called the Dominate. In the Dominate (from dominus, "lord" or "master" to a slave), power was divided between several Roman emperors who co-ruled different parts of the empire. The emperors of the Dominate gave up the pretense of being equal to elected officials; they wore lavish robes, and called themselves augusti and caesars rather than princeps. During this time the Senate was made pretty much irrelevant, and equestrian military families were promoted in their place.

The Byzantines and the Fall of Rome

It's often taught in history classes that Rome "fell" in 476 AD, but the truth is a bit more complicated. The Byzantine Empire, as they're often called, knew themselves as the Eastern Roman Empire. They continued many Roman traditions and considered themselves Roman for a long time. The Eastern Emperor Justinian even reconquered parts of the Western Empire and restored the Roman Senate. We haven't included the Eastern dynasties here, but they continued to rule from Constantinople until 1453--another 1000 years after the "Fall." 

So what happened in 476? In 476 a Roman military leader of Gothic descent, Flavius Odoacer, deposed the emperor and declared himself King of Italy. The Senate sent the imperial insignia to Constantinople, indicating that the seat of the empire was now officially in the East. Although Roman traditions would continue for a while after this--Odoacer even minted coins with the face of the emperor Julius Nepos--this is typically pointed to as the beginning of the Middle Ages and the end of Ancient Rome. 

Sources +