| | REIGNED. |
| | Years. | B.C. A.D. |
| Augustus | 40 | 27–14 |
| | A.D. |
| Tiberius | 23 | 14–37 |
| Caligula | 4 | 37–41 |
| Claudius | 13 | 41–54 |
| Nero | 14 | 54–68 |
| Galba | | 68–69 |
| Otho | | 69 |
| Vitellius | | 69 |
| Vespasian | 10 | 69–79 |
| Titus | 2 | 79–81 |
| Domitian | 15 | 81–96 |
| Nerva | 2 | 96–98 |
| Trajan | 19 | 98–117 |
| Hadrian | 21 | 117–138 |
| Antoninus Pius | 23 | 138–161 |
| { M. Aurelius | 19 | 161–180 |
| { L. Verus | 8 | 161–169 |
| Commodus | 12 | 180–192 |
| Pertinax | | 193 |
| Julianus | | 193 |
| Niger | | 194 |
| Septimius Severus | 18 | 193–211 |
| Albinus | 4 | 193–197 |
| { Caracalla | 6 | 211–217 |
| { Geta | 1 | 211–212 |
| Macrinus | 1 | 217–218 |
| Elagabalus | 4 | 218–222 |
| Alexander Severus | 13 | 222–235 |
| Uranius | | 223 |
| Maximinus | 3 | 235–238 |
| { Gordianus I. | | 238 |
| { Gordianus II. | | 238 |
| { Pupienus Maximus | | 238 |
| { Balbinus | | 238 |
| Gordianus III. | 6 | 238–244 |
| Philippus | 5 | 244–249 |
| Marinus | | 249 |
| Jotapinus | | 249 |
| Decius | 2 | 249–251 |
| Trebonianus Gallus | 3 | 251–254 |
| Æmilianus | | 253 |
| Volusianus | | 254 |
| { Valerian | 7 | 253–260 |
| { Gallienus | 15 | 253–268 |
| Macrianus | 2 | 260–262 |
| Regillianus | 2 | 261–263 |
| Postumus | 9 | 258–267 |
| Lælianus | | 267 |
| Victorinus | 2 | 265–267 |
| Marius | | 268 |
| Claudius II. | 2 | 268–270 |
| Quintillus | | 270 |
| Aurelian | 5 | 270–275 |
| Vabalathus | 5 | 266–271 |
| Tetricus | 5 | 268–273 |
| Tacitus | 1 | 275–276 |
| Florianus | | 276 |
| Probus | 6 | 276–282 |
| Bonosus | | 280 |
| Carus | 1 | 282–283 |
| { Carinus | 1 | 283–284 |
| { Numerianus | 1 | 283–284 |
| Julianus | | 284 |
| { Diocletian | 21 | 284–305 |
| { Maximianus | 19 | 286–305 |
| Carausius | 6 | 287–293 |
| Allectus | 4 | 293–297 |
| Constantius I. Chlorus | 1 | 305–306 |
| Galerius | 6 | 305–311 |
| Severus | 1 | 306–307 |
| Maximinus | 5 | 308–313 |
| Maxentius | 6 | 306–312 |
| Alexander | | 311 |
| Constantinus I. (the Great) | 31 | 306–337 |
| Licinius | 16 | 307–323 |
| { Constantinus II. | 3 | 337–340 |
| { Constantius II. | 24 | 337–361 |
| { Constans I. | 13 | 337–350 |
| Nepotianus | | 350 |
| Vetranio | 1 | 350–351 |
| Magnentius | 3 | 350–353 |
| Decentius | 2 | 351–353 |
| Constantius Gallus | 3 | 351–354 |
| Julianus II. | 2 | 361–363 |
| Jovianus | 1 | 363–364 |
| WESTERN EMPIRE. |
| Valentinianus I. | 11 | 364–375 |
| Valens | 14 | 364–378 |
| Procopius | 1 | 365–366 |
| Gratian | 16 | 367–383 |
| Valentinianus II. | 17 | 375–392 |
| Theodosius I. (Emperor of the West as well as of the East) | 3 | 392–395 |
| Maximus | 5 | 383–388 |
| Eugenius | 2 | 392–394 |
| Honorius | 28 | 395–423 |
| Constantius III. | | 421 |
| Constantinus III. | 4 | 407–411 |
| Constans | 3 | 408–411 |
| Maximus | 2 | 409–411 |
| Jovinus | 2 | 411–413 |
| Sebastianus | 1 | 412–413 |
| Priscus Attalus | 7 | 409–416 |
| Johannes | 2 | 423–425 |
| Theodosius II. (Emperor of the West as well as of the East) | 2 | 423–425 |
| Valentinian III. | 30 | 425–455 |
| Petronius Maximus | | 455 |
| Avitus | 1 | 455–456 |
| Majorianus | 4 | 457–461 |
| Libius Severus III. | 4 | 461–465 |
| Anthemius | 5 | 467–472 |
| Olybrius | | 472 |
| Glycerius | 1 | 473–474 |
| Julius Nepos | 1 | 474–475 |
| Romulus Augustulus | 1 | 475–476 |
| EASTERN EMPIRE. |
| Valens | 14 | 364–378 |
| Theodosius I. | 17 | 378–395 |
| Arcadius | 13 | 395–408 |
| Theodosius II. | 42 | 408–450 |
| Marcian | 7 | 450–457 |
| Leo I. (Thrax) | 17 | 457–474 |
| Leo II. | | 474 |
| Zeno | 17 | 474–491 |