List of Roman Emperors: Famous Rulers in History

The early period of the Roman Empire is known as the Principate (27 B.C. to A.D. 284 ). During this time, the Roman Empire was ruled by one emperor (the princeps). While the Roman Empire tried to maintain the traditions of the earlier Roman Republic, this people of Roman rule more closely resembled an autocracy where the emperor held most of the political power. Check out a list of the Roman emperors of the Principate.

When you think of a Roman emperor, the first image that comes to mind is likely Julius Caesar. However, Caesar was not an official Roman emperor. The title of Caesar later became an honorific title meaning "successor of the emperor," which is why many people mistake Julius Caesar as the first Roman emperor. The Julian-Claudian Dynasty began when Augustus became the first and best Roman emperor (according to many historians) in 27 B.C. (Augustus is the title meaning "emperor.") This period also includes Nero, whom many historians consider to be the worst Roman emperor.

• Augustus (27 B.C.-A.D. 14)
• Tiberius (A.D. 14-37)
• Caligula (A.D. 37-41)
• Claudius (A.D. 41-54)
• Nero (A.D. 54-68)

After Nero Claudius Caesar committed suicide in A.D. 68, the Roman Empire experienced a brief period of unrest. It saw four emperors ascend in a 12-month period, three of whom were dead before the end of 69 (Galba and Vitellius were killed shortly after taking power; Otho committed suicide after being defeated by Vitellius). Vespasian, the final emperor of this period, reigned for ten years and became the first emperor of the Flavian Dynasty.

• Galba (June 68-January 69)
• Otho (January 69-April 69)
• Vitellius (April 69-December 69)
• Vespasian (December 69-79)

The Flavian Dynasty held power for nearly 40 years at the end of the first century. Emperor Titus, son of Vespasian, was in rule during the eruption of Vesuvius in A.D. 79. His brother, Domitian, remained in power for 15 years before his assassination brought Marcus Cocceius Nerva forth as emperor.

• Vespasian (A.D. 69-79)
• Titus (A.D. 79-81)
• Domitian (A.D. 81-96)

The first five emperors of the Nerva-Antonine Dynasty are historically known as the Five Good Emperors. They were believed to be less oppressive and more moderate than previous Roman emperors. Many considered this quality to be shared among the Five Good Emperors because they were all adopted, not blood heirs to the throne, and chosen for their benevolence rather than military loyalty.

• Nerva (A.D. 96-98)
• Trajan (A.D. 98-117)
• Hadrian (A.D. 117-138)
• Antoninus Pius (A.D. 138-161)
• Marcus Aurelius (A.D. 161-180)
• Lucius Verus (ruled with father-in-law Marcus Aurelius from A.D. 161-169)
• Commodus (A.D. 180-192)

After the Five Good Emperors came the Year of the Five Emperors, where five different men competed for power after the murder of Commodus in A.D. 192. Pertinax was chosen but quickly assassinated; his successor, Didius Julianus, was executed in less than three months by Septimus Severus, who had claimed the title for himself. Pescennius Niger and Clodius Albinus also claimed the title of Emperor after Pertinax was killed, but were not accepted by the Senate.

• Pertinax (January-March 193)
• Didius Julianus (March-June 193)
• Septimius Severus (April 193-211)

The civil war that had arisen during the Year of the Five Emperors came to an end with the Severan Dynasty. The emperors were strongly influenced by the empresses of this dynasty (known as the Julias of Rome). This line of emperors would be the last of the Principate, which ended with the murder of Alexander Severus by Maximinus Thrax.

• Septimius Severus (A.D. 193-211)
• Caracalla (A.D. 211-217)
• Geta (ruled with brother Caracalla from A.D. 211-212)
• Macrinus (A.D. 217-218)
• Diadumenian (May-June 218)
• Elagabalus (A.D. 218-222)
• Severus Alexander (A.D. 222-235)

The republic of the Principate gave way to the despotism of the Dominate period, in which emperors seized power through violent means and lost it just as quickly. These leaders were more authoritarian and autocratic, hence the name Dominate ("to master or control"). Keep reading for a list of the Roman emperors of the Dominate period.

The Principate ended with the Crisis of the Third Century (A.D. 235-284), in which political instability and unrest threatened to destroy the Roman Empire. It included the Year of the Six Emperors in A.D. 238 in which five emperors were killed in rapid succession, before a series of emperors who only held power until someone could take it away.

• Maximinus Thrax (A.D. 235-238)
• Gordian I (March 238-April 238)
• Gordian II (ruled with his father from March 238-April 238)
• Puplenus (April 238-July 238)
• Balbinus (ruled with Puplenus from April 238-July 238)
• Gordian III (July 238-244)
• Philip the Arab (A.D. 244-249)
• Phillip II (ruled with father Philip from A.D. 247-249)
• Decius (A.D. 249-251)
• Herennius Etruscus (June 251)
• Hostilianus (June 251-November 251)
• Trebonianus Gallus (A.D. 251-253)
• Volusianus (ruled with father Trebonianus Gallus from A.D. 251-253)
• Aemilianus (July 253-September 253)
• Valerian (A.D. 253-260)
  
• Gallienus (ruled with father Valerian from A.D. 253-260, then alone from A.D. 260-268)
• Saloninus (shortly ruled with his father Gallienus from January 260-September 260)
• Claudius Gothicus (A.D. 268-270)
• Quintillus (A.D. April 270-May 270)
• Aurelian (A.D. 270-275)
• Tacitus (A.D. 275-276)
• Florianus (June 276-September 276)
• Probus (A.D. 276-282)
• Carus (A.D. 282-283)
• Carinus (A.D. 283-285)
• Numerianus (ruled with brother Carinus from A.D. 283-284)

When Diocletian was declared Emperor in A.D. 284, the Roman Empire changed forever. In A.D. 293 he declared that the Roman government would be ruled by two emperors (augustuses) and two junior emperors (caesares). This resulted in multiple emperors in the same time period, and ultimately, the territorial split of the Roman Empire into East and West.

The Four Tetrarchs are known as Diocletian, Maximian, Galerius, and Constantius I. The first two emperors were appointed Augustuses while the second two were Caesares. Galerius would eventually rule as Augustus until A.D. 311, after which a power struggle would ensue over his throne. Constantius would later begin the great Constantinian Dynasty.

• Diocletian (ruled with Maximian from A.D. 284-305)
• Maximian (ruled with Diocletian from A.D. 286-305)
• Galerius (served as Caesar from A.D. 293-305, then ruled as Augustus from 305-311)
• Constantius I (served as Caesar from A.D. 293-305, then ruled as Augustus from 305-306)
• Severus (A.D. 306-307)
• Maxentius (A.D. 306 -312)
• Licinius (A.D. 308-324)
• Maximinus Daza (A.D. 308-313)
• Valerius Valens (A.D. 316-317)
• Martinian (July 324-September 324)

Constantine I, son of Constantius I, reigned for 30 years during the fourth century. He was responsible for converting the Roman Empire to Christianity. Constantine I also founded the city of Constantinople in Byzantium, laying the groundwork for the Byzantine Empire. His three sons, Constantine II, Constans and Constantius II, would rule for over 20 more years.

• Constantius I the Great (served as Caesar from A.D. 293-305, then ruled as Augustus from A.D. 305-306)
• Constantine I (A.D. 306-337)
• Constantine II (A.D. 337-340)
• Constans (A.D. 337-350)
• Constantius II (A.D. 337-361)
• Vetranio (March 350-December 350)
• Julian the Apostate (A.D. 361-363)
• Jovian (A.D. 363-364)

Also known as the Valentinianic Dynasty, this line of emperors mainly oversaw the western regions of the Roman Empire. Galla, daughter of Valentinian I, married Theodosius the Great, emperor of the eastern territory. The short dynasty ended when two usurpers, Magnus Maximus and Eugenius, managed to take power in the West with Senate approval.

• Valentinian I (A.D. 364-375)
• Valens (A.D. 364-378)
• Gratian (A.D. 375-383)
• Valentinian II (A.D. 375-392)
• Magnus Maximus (usurper in the West; ruled from A.D. 383-388)
• Victor (A.D. 387-388)
• Eugenius (usurper in the West; ruled from A.D. 393-394)

The Theodosian Dynasty was the final dynasty of the Roman Empire. Theodosius I was the last emperor of the united Roman Empire; his sons, Honorius and Arcadius, took control over the western and eastern regions of the empire after his death. From that time on, the Roman Empire would always be split and ruled separately.

• Theodosius I the Great (A.D. 379-395)
• Honorius (ruled in the West from A.D. 395-423)
• Arcadius (ruled in the East from A.D. 395-408)
• Theodosius II (ruled in the East from A.D. 408-450)
• Constantine III (usurper in the West; ruled from A.D. 409-411)
• Constans II (ruled in the West from A.D. 409 -411)
• Constantius III (ruled in the West from February 421-September 421)
• Joannes (ruled in the West from A.D. 423-425)
• Valentinian III (ruled in the West from A.D. 425-455)
• Marcian (ruled in the East from A.D. 450-457)

The western territories of the Roman Empire began to shrink in its final years. Western Roman Emperors ruled over smaller regions for less time, and they were often not recognized by the eastern part of the Roman Empire. Some historians link the fall of the classical Roman Empire with the deposition of Romulus Augustulus, the last Western Roman Emperor.

• Petronius Maximus (March 455-May 455)
• Avitus (A.D. 455-456)
• Majorian (A.D. 457-461)
• Libius Severus (A.D. 461-465)
• Anthemius (A.D. 467-472)
• Olybrius (July 472-November 472)
• Glycerius (A.D. 473-474)
• Julius Nepos (A.D. 474-475)
• Romulus Augustulus (A.D. 474-476)

After the Western Roman Empire fell in A.D. 476, the Eastern Roman Empire transitioned into what we now refer to as the Byzantine Empire. Many historians begin the Byzantine Empire with the Constantinian Dynasty starting in A.D. 306, but others believe it began with the fall of Rome. Prominent Byzantine emperors include Zeno (A.D. 474-491), Basil II (A.D. 976-1025) and Constantine XI (A.D. 1405-1453), who was killed when the Byzantine Empire fell to the Ottoman Empire in 1453.

In the early Middle Ages, the power of the Roman emperors had a resurgence. It was inherited by the monarchs of Italy and later Germany, known as the Holy Roman Emperors. Charlemagne was the first emperor of the Holy Roman Empire, which stretched through Western and Central Europe, from A.D. 800 to 814. Notable Holy Roman Emperors included Otto I of the Ottonian Dynasty (A.D. 962-973), Charles V (A.D. 1519-1556) and Francis II (A.D. 1792-1806), who was the last emperor before the fall of the of Holy Roman Empire in the Napoleonic Wars.

The Roman Empire stretched both across the globe and through many eras in world history. Understanding the dynamics of these emperors can help us understand why current countries have the borders — and the histories — that they have today. For more stories from the past, check out a list of major time periods in history. You can also compare Greek and Roman gods and goddesses in your study of classical Roman culture.