SÃO PAULO, Brazil — As the old saying goes, “it’s good to be king” — unless you were an emperor in ancient Rome, a new study reveals. Although Italy is home to countless statues honoring the Romans who ascended to the title of Caesar, researchers say only a few of these leaders actually lived to see a long and happy reign. In fact, three in four appear to have suffered some very painful deaths.
Study authors from the University of São Paulo’s Institute of Mathematical and Computer Sciences report that only one in four (24.8% out of 69) Western Roman emperors died of natural causes. The rest were either killed in battle or during an underhanded political plot. If the team includes the Byzantine Empire, or Eastern portion of the Roman Empire, 30 percent of the 175 emperors in the study were either murdered, committed suicide, or died in battle.
The research team investigated the underlying mathematical patterns linked to the Caesars’ reigns, and concluded the pattern follows a “power law.”
“Although they appear to be random, power-law distributions of probabilities are found in many other phenomena associated with complex systems, such as lunar crater sizes, earthquake magnitudes, word frequencies in texts, the market value of companies, and even the number of ‘followers’ people have on social media,” data scientist Francisco Rodrigues, a professor at ICMC-USP and the study’s principal investigator, says in a media release.
The odds don’t look good for you, Caesar
While statistical talk and accompanying power laws can be pretty confusing, researchers say the majority of this pattern follows the “80/20” rule. This rule simply describes situations in which one outcome or observation occurs far more often than another. For example, 80 percent of craters on the Moon are small while 20 percent happen to be large. Similarly, 80 percent of social media users only have a few dozen followers or friends, while 20 percent boast larger numbers.
When it comes to Roman emperors, the rare event appears to be living a full and healthy life.
“The first person to observe this ratio was Italian economist Vilfredo Pareto (1848-1923). While studying wealth distribution in Europe, he found that 80% of Italy’s property belonged to 20% of its population. The majority had few resources, and a minority owned most of the wealth,” Prof. Rodrigues explains.
Study authors also observed another pattern among the ancient rulers. Apparently, the risk of death for a Roman emperor was highest right after taking the throne! The risk jumped up again for those holding power for over a decade.
“When we analyzed time to death for each emperor, we found that the risk was high when the emperor took the throne. This could have something to do with the difficulties and demands of the job and the new emperor’s lack of political expertise. The risk then declines systematically until the emperor has reigned for 13 years. At that point, it rises sharply again,” Prof. Rodrigues reports.
We’re sick of you, Caesar!
So why would the risk of assassination jump so sharply after 13 years in power? Study authors theorize that by that time, many of the ruler’s political rivals may have simply grown tired of waiting for their leader to die of old age.
“We envisaged several possible explanations for this turning-point. It may be that after the 13-year cycle the emperor’s rivals concluded they were unlikely to ascend the throne by natural means. Perhaps his old enemies regrouped, or new rivals may have come to the fore. A crisis may have arisen owing to all these factors combined. It’s worth noting that the risk falls again after this turning-point,” Prof. Rodrigues notes.
Statistics and history aren’t obvious bedfellows, but this groundbreaking research shows that statistical analysis can be an invaluable resource in the quest for further historical clarity and understanding.
“Historical formations are complex systems in which players interact, collaborate and compete for power and resources. The unpredictable actions of individuals can produce predictable patterns of collective behavior that can be investigated mathematically,” Prof. Rodrigues concludes.
The findings appear in the journal Royal Society Open Science.