The Roman Empire started in 27 BC and lasted until 476 AD. It is regarded as one of the most powerful and influential empires to have existed in human history. During this span, there were 90 solo emperors and/or co-emperors who ruled.
This article will look at these 90 emperors, with them being broken down into different eras of the Empire in terms of their length of rule and age at death. For the purposes of this article, it will count their total time as ruler, combining solo and co-emperorship.
Some emperors did not manage to rule for a whole year before dying. In order to manage this in the graphs below, I converted each month into a decimal to be represented on the graphs for those emperors.
Time as a fraction of one year
Length of rule and age at death for Roman Emperors in each period of the Roman Empire
*Lucius Verus and his son-in-law Marcus Aurelius were co-emperors from 161 to 169 (~7 years)
*Marcus Aurelius and his son Commodus ruled as joint emperors from 177 to 180 (~3 years)
*Didius Julianus is thought to have been 56 or 60 at the time of his execution
*Caracalla was co-emperor with Septimius Severus from 198 to 209 (~11 years)
*Caracalla, Severus, and Geta ruled as co-emperors from 209 to 211 (~2 years)
*Caracalla and Geta ruled as co-emperors in 211
*Macrinus made his son Diadumenian co-emperor one month into his reign
*Gordian I and his son Gordian II were joint-emperors for 21 days during their failed revolt against Maximinus Thrax
*Pupienus, Balbinus and Gordian III were joint-emperors for three months
*Pupienus is thought to have been 68 or 73 at the time of his death
*Philip the Arab and his son Philip the II were co-emperors from 247 to 249 (~2 years)
*Decius and his son Herennius Etruscus were co-emperors in 251
*Hostilian was emperor for 4-5 months (I went with the higher number in the chart above)
*Trebonianus Gallus and his son Volusianus were co-emperors from 251-253 (~2 years)
*Aemilian was thought to be either 40 or 46 at the time of his assassination
*Saloninus was briefly co-emperor to his father Gallienus for about one month before being assassinated
*Aurelian was either 60 or 61 at the time of his assassination
*Carus and Carinus ruled as co-emperors in 283
*Numerian and Carinus ruled as co-emperors from 284-285 (~1 year)
*It is unknown how old Florianus, Numerian or Carinus were
*Diocletian and Maximian were co-emperors from 286 to 305 (~19 years)
*Galerius and Constantius Chlorus were co-emperors from 305 to 306 (~1 year)
*Galerius and Valerius Severus were co-emperors from 306 to 307 (~1 year)
*Galerius and Constantine the Great were co-emperors from 307 to 311 (~4 years)
*Maxentius was made emperor in the West in opposition to Constantine the Great in 307
*Licinius I was made emperor in the West to oppose Maxentius in 308. In 311, he became emperor of the East following the death of Galerius.
*Licinius I and Maximus II were co-emperors in the East from 211 to 213 (~2 years) until Licinius defeated him in a civil war.
*Licinius I and his son Valerius Valens were co-emperors from late 316 to March 317 (at most 5 months time).
*Licinius I and his son Martinian were co-emperors in 324
*Constantine II, Constans and Constantius II were co-emperors from 337 to 340 (~3 years)
*Constans and Constantius II were co-emperors from 340 to 350 (~10 years)
*Julian was either 30 or 31 when he died due to a wound he suffered during the Battle of Samarra.
*It is unknown how old Valerius Severus, Valerius Valens, Martinian, and Vetranio were
*Valentinian I and Valens were co-emperors from 364 to 367 (~3 years)
*Valentinian I, Valens and Gratian were co-emperors from 367 to 375 (~8 years)
*Valens, Gratian and Valentinian II were co-emperors from 375 to 378 (~3 years)
*Gratian and Valentinian II were co-emperors from 378 to 383 (~5 years)
Theodosius I was the last person to rule both halves of the Roman Empire. At this point, rulers in the West are not considered Roman rulers for the purpose of this article.
*Magnus Maximus and his son Flavius Victor were co-emperors for 4 or 5 years (I split the difference in the chart above)
*It is unknown how old Flavius Victor was at the time of his execution
*Theodosius I and Honorius were co-emperors from 393 to 395 (~2 years)
*Constantine II was recognized as co-emperor by Honorius in 209. They were co-emperors until 211
*Constans II was co-emperor to Constantine II from 209 to 211 (~2 years) but was not recognized by Honorius
*Constantius III and Honorius were co-emperors in 221
*Joannes and Valentinian III were in opposition to each other from 323 to 324 until Joannes execution
*It is unknown how old Constantine II, Constans II, Constantius III and Joannes were
*Petronius Maximus was either 58 or 59 at the time of his murder
*Julius Nepos was deposed by Flavius Orestes (father of Romulus Augustulus) but was maintained as a figurehead by Odoacer (the first King of Italy) until Nepos was assassinated in 480.
*Romulus Augustulus was never recognized as emperor by Eastern Emperor Zeno and was deposed by Odoacer in 476.
Length of rule for all Roman Emperors
Only 25 of the 90 (27.77%) of the Roman Emperors ruled for more than 10 years. Meanwhile, 34 (37.77%) ruled for one year or less.
|Emperors/co-emperors to rule over 20 years||Length of Rule (Time)|
|Augustus||27 BC-14 AD (40 years, 7 months and 3 days)|
|Constantine the Great||306-337 (30 years, 9 months and 27 days)|
|Honorius||393-423 (30 years, 6 months and 23 days)|
|Valentinian III||424-455 (30 years, 4 months and 21 days)|
|Constantius II||337-361 (24 years, 5 months and 12 days)|
|Antoninus Pius||138-161 (22 years, 6 months and 28 days)|
|Tiberius||14-37 (22 years, 5 months and 27 days)|
|Hadrian||117-138 (20 years, 10 months and 30 days)|
|Diocletian||284-305 (20 years, 5 months and 11 days)|
|Emperors/co-emperors to rule less than 6 months||Length of Rule (Time)||Cause of death|
|Valerius Valens||316-317 (~5 months, Late 316 to March 1st 317)||Executed|
|Hostilian||251 (4-5 months)||Likely died from Natural causes (Plague)|
|Olybrius||472 (3 months and 22 days)||Natural causes (Dropsy, aka Edema)|
|Pupienus||238 (3 months and 7 days)||Assassinated by Praetorian Guard|
|Balbinus||238 (3 months and 7 days)||Assassinated by Praetorian Guard|
|Otho||69 (3 months and 1 day) (91 days)||Committed suicide after losing Battle of Bedriacum|
|Florianus||276 (3 months)||Assassinated by his own troops|
|Pertinax||193 (2 months and 27 days) (86 days)||Assassinated by Praetorian Guard|
|Petronius Maximus||455 (2 months and 14 days) (75 days)||Murdered, likely by an angry mob|
|Didius Julianus||193 (2 months and 4 days) (65 days)||Executed on orders from the Senate|
|Aemilian||253 (2 months)||Assassinated by own troops|
|Martinian||324 (~2 months, July to September 18th)||Executed in 325|
|Saloninus||260 (~1 month, July to August)||Murdered by Postumus’ army|
|Gordian I||238 (21 days)||Committed suicide after learning of his son’s death|
|Gordian II||238 (21 days)||Killed during the Battle of Carthage|
Age at death for all Roman Emperors
I decided to keep in the emperors whose age at death is unknown in this chart.
|Emperors/co-emperors who died over 70 or under 20||Age at death||Years during Reign (Time)|
|Gordian I||79||238 (21 days)|
|Tiberius||77||14-37 (22 years, 5 months and 27 days)|
|Tacitus||76||275-276 (9 months)|
|Augustus||75||27 BC-14 AD (40 years, 7 months and 3 days)|
|Antoninus Pius||74||138-161 (22 years, 6 months and 28 days)|
|Avitus||71||457-461 (4 years)|
|Galba||70||68-69 (7 months and 7 days)|
|Gordian III||19||238-244 (5 years, 9 months and 20 days)|
|Elagabalus||18||218-222 (3 years, 9 months and 3 days)|
|Saloninus||18||260 (~Late July)|
|Philip II||12||247-249 (~2 years)|
|Diadumenian||10||218 (May to June)|
At 79 Gordian I was the oldest person to become emperor. Meanwhile, his grandson Gordian III was the longest person to become sole emperor of Rome at age 13.
Sources and notes:
https://www.checkyourmath.com/convert/time/months_years.php (Used to get decimal numbers shown in the month table)
All graphs and tables made using Google Spreadsheet