| Augustus | Gaius Julius Caesar Augustus |
| Julio-Claudian Dynasty | 27 BC - AD 14 |
| Tiberius | Tiberius Julius Caesar Augustus |
| Julio-Claudian Dynasty | AD 14-37 |
| Caligula | Gaius Caesar Augustus Germanicus |
| Julio-Claudian Dynasty | AD 37-41 |
| Claudius | Tiberius Claudius Caesar Augustus Germanicus |
| Julio-Claudian Dynasty | AD 41-54 |
| Nero | Nero Claudius Caesar Augustus Germanicus |
| Julio-Claudian Dynasty | AD 54-68 |
| Galba | Servius Sulpicius Galba |
| Year of the Four Emperors | AD 68 to 69 |
| Otho | Marcus Salvius Otho |
| Year of the Four Emperors | January to April AD 69 (3 months) |
| Vitellius | Aulus Vitellius |
| Year of the Four Emperors | April 19 to December 20 AD 69 |
| Vespasian | Titus Flavius Vespasianus |
| Flavian Dynasty | AD 69 to AD 79 |
| Titus | Titus Caesar Vespasianus |
| Flavian Dynasty | AD 79 - 81 |
| Domitian | Titus Flavius Domitianus |
| Flavian Dynasty | AD 81 to 96 |
| Nerva | Marcus Cocceius Nerva |
| Nerva–Antonine Dynasty | AD 96 - 98 |
| Trajan | Marcus Ulpius Traianus |
| Nerva–Antonine Dynasty | AD 98 - 117 |
| Hadrian | Publius Aelius Hadrianus |
| Nerva–Antonine Dynasty | AD 117 to 138 |
| Antoninus Pius | Titus Aelius Hadrianus Antoninus Pius |
| Nerva–Antonine Dynasty | AD 138 - 161 |
| Marcus Aurelius | Marcus Aurelius Antoninus |
| Nerva–Antonine Dynasty | AD 161 to 180 |
| Lucius | Lucius Aurelius Verus |
| Nerva–Antonine Dynasty | 161 - 169 |
| Commodus | Marcus Aurelius Commodus Antoninus / Lucius Aelius Aurelius Commodus |
| Nerva–Antonine Dynasty | 177 - 192 |
| Pertinax | Publius Helvius Pertinax |
| Year of the Five Emperors | 2 months and 27 days in AD 193 |
| Julianus | Marcus Didius Severus Julianus |
| Year of the Five Emperors | March to June 193 (66 days) |
| Septimius Severus | Lucius Septimius Severus Pertinax |
| Severan Dynasty | 9 April 193 – 4 February 211 |
| Caracalla | Marcus Aurelius Antoninus |
| Severan Dynasty | 198 - 217 AD |
| Geta | Publius Septimius Geta |
| Severan Dynasty | 4 February 211 – 26 December 211 |
| Macrinus | Marcus Opellius Severus Macrinus |
| Severan Dynasty | 11 April 217 – 8 June 218 |
| Diadumenian | Marcus Opellius Antoninus Diadumenianus |
| Severan Dynasty | May 217 - June 218 |
| Elagabalus | Marcus Aurelius Antoninus |
| Severan Dynasty | 218 - 222 (3 years, 9 months ) |
| Severus Alexander | Marcus Aurelius Severus Alexander |
| Severan Dynasty | 13 March 222 – 21 March 235 |
| Maximinus I "Thrax" | Gaius Julius Verus Maximinus |
| Crisis of the Third Century | c. March 235 - June 238 |
| Gordian I | Marcus Antonius Gordianus Sempronianus Romanus |
| Crisis of the Third Century | c. April – c. May 238 (22 days) |
| Gordian II | Marcus Antonius Gordianus Sempronianus Romanus |
| Crisis of the Third Century | 238 - 22 days |
| Pupienus | Marcus Clodius Pupienus Maximus |
| Crisis of the Third Century | c. May – c. August 238 (99 days) |
| Balbinus | Decimus Caelius Calvinus Balbinus |
| Crisis of the Third Century | c. May – c. August 238 (99 days) |
| Gordian III | Marcus Antonius Gordianus |
| c. August 238 – c. February 244 (c. 5 years and 6 months) | |
| Philip I "the Arab" | Marcus Julius Philippus |
| Crisis of the Third Century | c. February 244 – September/October 249 (c. 5 years and 7/8 months) |
| Philip II "The Younger" | Marcus Julius Severus Philippus |
| Crisis of the Third Century | July/August 247 – September/October 249 (c. 2 years and 2 months) |
| Decius | Gaius Messius Quintus Traianus Decius |
| Crisis of the Third Century | September/October 249 – June 251 (c. 1 year and 8/9 months) |
| Herennius Etruscus | Quintus Herennius Etruscus Messius Decius |
| Crisis of the Third Century | May/June – June 251 (less than a month) |
| Trebonianus Gallus | Gaius Vibius Trebonianus Gallus |
| Crisis of the Third Century | June 251 – c. August 253 (c. 2 years and 2 months) |
| Hostilian | Gaius Valens Hostilianus Messius Quintus |
| Crisis of the Third Century | c. June – c. July 251 (c. 1 month) |
| Volusianus | Gaius Vibius Afinius Gallus Veldumnianus Volusianus |
| Crisis of the Third Century | c. August 251 – c. August 253 (2 years) |
| Aemilianus | Marcus Aemilius Aemilianus |
| Crisis of the Third Century | c. July – c. September 253 (88 days?) |
| Silbannacus | Marcius or Marius Silbannacus |
| Crisis of the Third Century | c. September/October 253 (?) (very briefly?) |
| Valerian | Publius Licinius Valerianus |
| Crisis of the Third Century | c. September 253 – c. June 260 (c. 6 years and 9 months) |
| Gallienus | Publius Licinius Egnatius Gallienus |
| Crisis of the Third Century | c. September 253 – c. September 268 (15 years) |
| Saloninus | Publius Licinius Cornelius Saloninus Valerianus |
| Crisis of the Third Century | Autumn 260 (c. 1 month) |
| Claudius II "Gothicus" | Marcus Aurelius Claudius |
| Crisis of the Third Century | c. September 268 – c. August 270 (c. 1 year and 11 months) |
| Quintillus | Marcus Aurelius Claudius Quintillus |
| Crisis of the Third Century | c. August – c. September 270 (c. 27 days) |
| Aurelian | Lucius Domitius Aurelianus |
| Crisis of the Third Century | c. August 270 – c. November 275 (c. 5 years and 3 months) |
| Tacitus | Marcus Claudius Tacitus |
| Crisis of the Third Century | c. December 275 – c. June 276 (c. 7 months) |
| Florianus aka Florian | Marcus Annius Florianus |
| Crisis of the Third Century | c. June – September 276 (80–88 days) |
| Probus | Marcus Aurelius Probus |
| Crisis of the Third Century | c. June 276 – c. September 282 (c. 6 years and 3 months) |
| Carus | Marcus Aurelius Carus |
| Crisis of the Third Century | c. September 282 – c. July 283 |
| Carinus | Marcus Aurelius Carinus |
| Crisis of the Third Century | Spring 283 – August/September 285 (2 years) |
| Numerian | Numerian Marcus Aurelius Numerianus |
| Crisis of the Third Century | c. July/August 283 – November 284 (1 year and 3/4 months) |
| Diocletian "Jovius" | Gaius Aurelius Valerius Diocletianus |
| Tetrachy | 20 November 284 – 1 May 305 (20 years, 5 months and 11 days) Whole; then East |
| Maximian "Herculius" | Marcus Aurelius Valerius Maximianus |
| Tetrachy | 1 April 286 – 1 May 305 (19 years and 1 month; West) Late 306 – 11 November 308 (2 years; Italy) |
| Galerius | Gaius Galerius Valerius Maximianus |
| Tetrachy | 1 May 305 – May 311 (6 years; East) |
| Constantius I "Chlorus" | Marcus Flavius Valerius Constantius |
| Tetrachy | 1 May 305 – 25 July 306 (1 year, 2 months and 24 days; West) |
| Severus II | Flavius Valerius Severus |
| Tetrachy | August 306 – March/April 307 (c. 8 months; West) |
| Maxentius | Marcus Aurelius Valerius Maxentius |
| Tetrachy | 28 October 306 – 28 October 312 (6 years; Italy) |
| Licinius | Valerius Licinianus Licinius |
| Tetrachy | 11 November 308 – 19 September 324 (15 years, 10 months and 8 days) West; then East |
| Maximinus II "Daza" | Galerius Valerius Maximinus |
| Tetrachy | 310 – c. July 313 (3 years; East) |
| Valerius Valens | Aurelius Valerius Valens |
| Tetrachy | October 316 – c. January 317 (c. 2–3 months; West) |
| Martinian | Mar. Martinianus |
| Tetrachy | July – 19 September 324 (2 months; West) |
| Constantine I ("the Great") | Flavius Valerius Constantinus |
| Constantinian Dynasty | 25 July 306 – 22 May 337 (30 years, 9 months and 27 days) West; then whole |