Roman Emperors and Their Rule

New! If you enjoyed this, don’t forget to read Timeline of Ancient Egypt—Pharaohs and Their Rule in Charts

The Roman empire is a fascinating period in history. We mostly read about the “famous times” of Caesar, Antony, and Octavian (later Augustus), but not much about the long reign of emperors, starting with Octavian in 27 BC, all the way close to 500 AD. It’s a period rich with colorful characters and world-changing events.

When we watch TV serials or movies about Rome, we rarely get an idea of the numbers behind the period — how many emperors were really there? How long did they often rule? It sometimes feels like someone came to power, got murdered 6 days later, and *boom* the next guy’s on and so on.

Wasn’t really the case.

This post is an attempt to give the reader an idea of the scale and times, with some interesting facts and tidbits to go along with it.

A few notes first

  • The source for much of the data is — so the responsibility of the choice of source and any inaccuracies is mine

  • There are always exceptions — some emperors ruled jointly, the period of some is unclear, how some died is unknown, and I’ve rounded their rule to the nearest year — so those who were in power for 3 months would be 0

  • We start with Augustus Caesar as the first Roman emperor starting in 27 BC

There were about 70 Roman emperors from the beginning (Augustus — 27 BC) until the end (Romulus Augustus — 476 AD). Let’s look at the rule of the first 25 emperors, and the ~number of years each one ruled. Keep in mind that while the period is chronological, some emperors were joint rulers.

Years in rule

The first 25 Roman emperors and their ruling periods in years

The first 25 Roman emperors and their ruling periods in years

  • Augustus, the first emperor, was also the longest ruling emperor — it’s impressive that once he took control after the civil war, he was able to rule and control a growing empire peacefully for over 40 years. That’s a long time when you think about it!

  • An interest observation is the “period of good emperors” from the beginning of Trajan. Domitian was a good administrator but hated by the Senate, and after his murder and short reign of Nerva, Trajan came to power. He’s known as among the best emperors in Roman history. Starting with him we have almost 80 years of consecutive, stable rule. Romans born in this time would have experienced a relatively peaceful period for almost their entire generation — from grandfather to grandchild, considering the life expectancy during the period

  • Those who watched Ridley Scott’s gladiator would have thought that Commodus killed his father Marcus Aurelius and became emperor. Though, in reality, Aurelius died of old age, and Commodus had already been a joint emperor with him for 3 years. Lucius Verus wasn’t in between Aurelius and Commodus — he was a joint emperor with Aurelius though he wasn’t too well known

    Now let’s look at those that ruled the longest periods

The top 25 emperors by their years of rule

The top 25 emperors by their years of rule

  • If you were born when Augustus assumed power, chances were you died before he died! (life expectancy was on an average of 35 years). Now imagine living under a modern democracy with the same president or prime minister your entire life

  • Constantine the great, the Roman emperor who made Christianity the state religion, was the second longest ruling emperor

  • How many of us have heard of Constantius II? While he ruled a few years as a joint emperor, he was there for nearly 25 years

  • It feels like the 15–20 band is a threshold even for powerful emperors. I think it’s because unless they became rulers quite young (like Augustus), they ran against old age, and with the absence of medical technology that we have today, they seem to have run up against mother nature if they didn’t get murdered as they got old and/or senile

  • Nero wasn’t a great ruler, so imagine living 14 years under him. So if you graduated university when he ascended the throne, you were there until you had nearly 15 years of job experience — a long time

  • Valerian, having ruled 7 years, was the only Roman emperor to die in captivity (how he was treated by the Persians is disputed)

    Now let’s look at causes of death


Roman emperors — causes of death and years in rule

What were the chances you died unnaturally (murder, suicide, battle, captivity) if you were emperor? Turns out, pretty high as expected

  • 28% of the Roman emperors who died of natural causes ruled for just over 50% of the total time- it bears that those that had stable, long reigns were because they were pretty good emperors and figured out how to keep assassins at bay

  • Those who died of natural causes ruled ~12 years each, and those murdered only 5. It’s almost as if the nature of those emperors caused their short life

  • A full 51% died unnaturally, and when we include the ‘unclear’ it becomes 73%. If you were a Roman emperor, there was a 3 in 4 chance of you dying not the way you really wanted to (Domitian was stabbed in the groin — ouch!)

  • There is a potential slight skew here — I’ve classified Augustus’ death as natural, though there’s some speculation that his wife Livia poisoned him, of his own accord


The Roman empire ruled for a long time, with many emperors lasting for decades in their rule and not days like we sometimes feel it is. While this article is about the Roman period, there are many other interesting empires one can research—Egyptians, Mauryans, Macedonians, Assyrians, Chinese—and so on. It’s a fascinating world!

If you’re an ancient history buff, you should check out my novels.

New! If you enjoyed this, don’t forget to read Timeline of Ancient Egypt—Pharaohs and Their Rule in Charts