The reigns and deaths of the Roman Emperors

Ah, the Roman Empire. One of the greatest empires to conquer the known world of ancient Europe. At its height, every man desired to sit on the throne, making the Roman Emperor one of the more precarious roles in ancient history. We always hear about the greatest and worst Emperors — Caesar Augustus and Caligula, for example — but we so rarely hear about the other Emperors who lost their lives in service of — and sometimes in detriment to — the Empire.

A few weeks ago, someone on /r/dataisbeautiful charted out the length of the reigns of each King and Queen of England and how they ultimately met their end. (Spoiler: The royal line didn’t seem very healthy.) Then earlier this week, another user charted out the causes of death of the Roman Emperors. It seemed only natural to combine the two to show the reigns and deaths of the Roman Emperors. All of this data comes from Wikipedia, who already had the entire line of Emperors sorted out into a table.

roman-emperor-reigns-deaths

Click on the image for a larger version

In the visualization above, we see the fairly sordid history of the Roman Empire. Well over half of the Emperors met some form of premature and violent end, with the average reign lasting only 8 years throughout the history of the Empire. Most of these violent ends are attributable to a particularly unstable period of the Empire known as the Crisis of the Third Century, where over 20 men (Maximinus I -> Carinus) — mostly prominent Generals of the army — ascended to the throne in a mere 50-year period. Nearly all of the Emperors during this period died violently, either by assassination or in battle.

The Crisis only came to an end when Diocletian, a military commander of low birth, came into power. Diocletian realized that the Empire was too large for one man to rule, and thus split the rule of the Empire with 3 other men, forming a tetrarchy, or “rule of four.” Thanks to Diocletian’s guidance and reforms, the Empire managed to hold together for another century despite The Crisis nearly tearing it apart. Diocletian is the only Emperor to have voluntarily abdicated from the throne, although it must have been tragic for him to watch the Empire crumble despite his life’s work rebuilding it.

The Roman Empire as we know it ended with Theodosius I who, despite his efforts, could not secure the Empire for his sons. His sons quickly lost control of the throne and the Empire fell into turmoil again, eventually leading to the sack of Rome in 410 AD and the eventual dissolution of the Western Roman Empire. The Eastern Roman Empire — later known as the Byzantine Empire — survived and even thrived for another millennium until it was conquered in 1453 AD.

Want to learn more about Roman history? I highly recommend this excellent podcast called The History of Rome.

Dr. Randy Olson is a Senior Data Scientist at the University of Pennsylvania, where he develops state-of-the-art machine learning algorithms with a focus on biomedical applications.

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  • Travis

    I’m sorry, but I don’t find this chart very useful. To me, the story it tells is that some Roman Emperors rules a long time, some did not. Completely separately it seems like they died from separate causes. The emperors with short periods of rule, I cannot tell how they died. There is nothing inherent in the chart to indicate this is a continuous stretch of history, or what the ordering of the rulers are.

    Because we are talking about history, I think some sort of visualization with an inherent time element like a timeline (although that’s better for showing overlap or gaps in between years; not a great choice either).

    I think part of the problem is taking a time-based data series and forcing it into a bar chart. Adding color for another dimension doesn’t make the chart more intuitive.

    • Hi Travis! Thanks for your comment.

      You’re right that the emperors who reigned only shortly are somewhat hard to see on this chart. My first thought at a workaround for that would be to log scale this chart, but that seems like an odd thing to do when the largest value is in the double digits.

      Time is actually represented on the x-axis: The emperors are ordered in the order that they reigned. So Augustus was the first emperor and Theodosius was the last emperor.

  • Seth

    I think this is really interesting, but can’t read the most interesting part of the data as I am red green color blind. Have you considered a different method of of visualizing the bars?

    • Oh shoot, that totally slipped my mind this time because I was replicating the color scheme from the previous version. If I remade this, I would instead use Tableau’s color blind 10 color scheme.

  • Jonas

    There are some suspiciously short-lived Roman Emperors, whos cause of death is nonetheless classified as ‘Natural causes’, ‘Suicide’ or ‘Illness’.