Roman Imperial Dates

This list of Roman emperors goes from the first emperor (Octavian, who is better known as Augustus) to the last emperor in the West (Romulus Augustulus). In the East, the Roman Empire continued until Constantinople (Byzantium) was sacked in A.D. 1453. This takes you through the standard period of Roman emperors, from the end of the 1st century B.C. to the end of the 5th century A.D.

During the second period of the Roman Empire, the Dominate — as opposed to the earlier period which was known as the Principate, there was an emperor at Constantinople as well as the one in the West. Rome was originally the capital of the Roman emperor. Later, it moved to Milan, and then Ravenna (A.D. 402-476). After the fall of Romulus Augustulus, in A.D. 476, Rome continued to have an emperor for almost another millennium, but that Roman emperor ruled from the East.

Julio-Claudians

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

Year of the 4 Emperors

(ends with Vespasian)68 - 69 Galba
69 Otho
69 Vitellius

Flavian Dynasty

69 - 79 Vespasian
79 - 81 Titus
81 - 96 Domitian

5 Good Emperors

96 - 98 Nerva
98 - 117 Trajan
117 - 138 Hadrian
138 - 161 Antoninus Pius
161 - 180 Marcus Aurelius
(161 - 169 Lucius Verus)

The next cluster of emperors is not part of a specific dynasty or other common grouping, but includes 4 from the year of the 5 emperors, 193.
177/180 - 192 Commodus
193 Pertinax
193 Didius Julianus
193 - 194 Pescennius Niger
193 - 197 Clodius Albinus

Severans

193 - 211 Septimius Severus
198/212 - 217 Caracalla
217 - 218 Macrinus
218 - 222 Elagabalus
222 - 235 Severus Alexander

More emperors without a dynastic label, although it includes the year of the 6 emperors, 238.
235 - 238 Maximinus
238 Gordian I and II
238 Balbinus and Pupienus
238 - 244 Gordian III
244 - 249 Philip the Arab
249 - 251 Decius
251 - 253 Gallus
253 - 260 Valerian
254 - 268 Gallienus
268 - 270 Claudius Gothicus
270 - 275 Aurelian
275 - 276 Tacitus
276 - 282 Probus
282 - 285 Carus Carinus Numerian

Tetrarchy

285-ca.310 Diocletian
295 L. Domitius Domitianus
297-298 Aurelius Achilleus
303 Eugenius
285-ca.310 Maximianus Herculius
285 Amandus
285 Aelianus
Iulianus
286?-297? British Emperors
286/7-293 Carausius
293-296/7 Allectus
293-306 Constantius I Chlorus

Dynasty of Constantine

293-311 Galerius
305-313 Maximinus Daia
305-307 Severus II
306-312 Maxentius
308-309 L. Domitius Alexander
308-324 Licinius
314? Valens
324 Martinianus
306-337 Constantinus I
333/334 Calocaerus
337-340 Constantinus II
337-350 Constans I
337-361 Constantius II
350-353 Magnentius
350 Nepotian
350 Vetranio
355 Silvanus
361-363 Julianus
363-364 Jovianus

Here are more emperors without a dynastic label.
364-375 Valentinianus I
375 Firmus
364-378 Valens
365-366 Procopius
366 Marcellus
367-383 Gratian
375-392 Valentinianus II
378-395 Theodosius I
383-388 Magnus Maximus
384-388 Flavius Victor
392-394 Eugenius

395-423 Honorius [Division of the Empire - Honorius' brother Arcadius ruled the East 395-408]
407-411 Constantine III usurper
421 Constantius III
423-425 Johannes
425-455 Valentinian III
455 Petronius Maximus
455-456 Avitus
457-461 Majorian
461-465 Libius Severus
467-472 Anthemius
468 Arvandus
470 Romanus
472 Olybrius
473-474 Glycerius
474-475 Julius Nepos
475-476 Romulus Augustulus