| Augustus, grandnephew of Julius Caesar, 27 B.C.-A.D. 14 |
| Tiberius, stepson of Augustus, A.D. 14-A.D. 37 |
| Caligula, grandnephew of Tiberius, 37-41 |
| Claudius, uncle of Caligula, 41-54 |
| Nero, stepson of Claudius, 54-68 |
| Galba, proclaimed emperor by his soldiers, 68-69 |
| Otho, military commander, 69 |
| Vespasian, military commander, 69-79 |
| Vitellius, military commander, 69 |
| Titus, son of Vespasian, 79-81 |
| Domitian, son of Vespasian, 81-96 |
| Nerva, elected interim ruler, 96-98 |
| Trajan, adopted son of Nerva, 98-117 |
| Hadrian, ward of Trajan, 117-38 |
| Antoninus Pius, adopted by Hadrian, 138-61 |
| Marcus Aurelius, adopted by Antoninus Pius, 161-80 |
| Lucius Verus, adopted by Antoninus Pius; ruled jointly Marcus Aurelius, 161-69 |
| Commodus, son of Marcus Aurelius, 180-92 |
| Pertinax, proclaimed emperor by the Praetorian Guard, 193 |
| Didius Julianus, bought office from the Praetorian Guard, 193 |
| Severus, proclaimed emperor, 193-211 |
| Caracalla, son of Severus, 211-17 |
| Geta, son of Severus, ruled jointly with Caracalla, 211-12 |
| Macrinus, proclaimed emperor by his soldiers, 217-18 |
| Heliogabalus, cousin of Caracalla, 218-22 |
| Alexander Severus, cousin of Heliogabalus, 222-35 |
| Maximin, proclaimed emperor by soldiers, 235-38 |
| 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, 238-44 |
| Philip (the Arabian), assassin of Gordian III, 244-49 |
| Decius, proclaimed emperor by the soldiers, 249-51 |
| Hostilianus, son of Decius, colleague of Gallus, 251 |
| Gallus, military commander, 251-53 |
| Aemilianus, military commander, 253 |
| Valerian, military commander, 253-60 |
| Gallienus, son of Valerian, coemperor with his father and later sole emperor, 253-68 |
| Claudius II, military commander, 268-70 |
| Aurelian, chosen by Claudius II as successor, 270-75 |
| Tacitus, chosen by the senate, 275-76 |
| Florianus, half brother of Tacitus, 276 |
| Probus, military commander, 276-82 |
| Carus, proclaimed by the Praetorian Guard, 282-83 |
| Carinus, son of Carus, 283-85 |
| Numerianus, son of Carus, joint emperor with Carinus, 283-84 |
| Diocletian, military commander, divided the empire; ruled jointly with Maximian and Constantius I, 284-305 |
| Maximian, appointed joint emperor by Diocletian, 286-305 |
| Constantius I, joint emperor and successor of Diocletian, 305-6 |
| Galerius, joint emperor with Constantius I, 305-10 |
| Maximin, nephew of Galerius, 308-13 |
| Licinius, appointed emperor in the West by Galerius; later emperor in the East, 308-24 |
| Maxentius, son of Maximian, 306-12 |
| Constantine I (the Great), son of Constantius I, 306-37 |
| Constantine II, son of Constantine I, 337-40 |
| Constans, son of Constantine I, 337-50 |
| Constantius II, son of Constantine I, 337-61 |
| Magnentius, usurped Constans' throne, 350-53 |
| Julian (the Apostate), nephew of Constantine I, 361-63 |
| Jovian, elected by the army, 363-64 |
| Valentinian I, proclaimed by the army; ruled in the West, 364-75 |
| Valens, brother of Valentinian I; ruled in the East, 364-78 |
| Gratian, son of Valentinian I; coruler in the West with Valentinian II, 375-83 |
| Maximus, usurper in the West, 383-88 |
| Valentinian II, son of Valentinian I, ruler of the West, 375-92 |
| Eugenius, usurper in the West, 393-94 |
| Theodosius I (the Great), appointed ruler of the East, 379-95, by Gratian; last ruler of united empire, 394-95 |
