File photo: A life-size bust of Julius Caesar is seen on the new buildings of the Department of underwater and undersea archaeological (DRASSM) in Marseilles, January 22, 2009. REUTERS/Jean-Paul Pelissier
Ancient Rome was a dangerous place for an emperor. During the more than 500 years, approximately 20 percent of the city’s 82 emperors were murdered, while on the power. So, what has led to their demise?
According to a new study, we can blame it on the rain.
Here is the reasoning: If the rainfall was low, troops in the Roman military, which was dependent on rain to water crops grown by local farmers — would have starved. “In turn, that would have pushed them over the edge to a potential mutiny,” said study principal investigator Cornelius Christian, an assistant professor in the economics of Brock University in Ontario, Canada. [Photos: the Old House and the Barracks of the Roman Military]
“And that mutiny, in turn, would collapse support for the emperor and him more likely to murder,” Christian told Live Science.
Christian, who considers himself as an economic historian, made the discovery using old climate data from a 2011 study in the journal Science. In that study, researchers analyzed thousands of fossilized tree rings from France and Germany, and calculated how much it had rained there (in millimeters) every spring for the past 2,500 years. This area once consisted of the Roman border, where soldiers were stationed.
Then, Christian pulled data about military rebellions, and emperor murders in ancient Rome. From there, “it was really just a matter of piecing together these various bits of information,” Christian said. He plugged the numbers into a formula and found that “lower rainfall means that there is more chance of killings that are to take place, because lower rainfall means less food.”
Take, for example, the Emperor Vitellius. He was assassinated in A. D. 69, a year of low precipitation on the Roman border, where the troops were stationed. “Vitellius was acclaimed emperor by his troops,” Christian said. “Unfortunately, the low rainfall hit of that year, and he was in shock. His troops revolted, and eventually he was murdered in Rome.”
But, as is often the case, many factors can lead to a murder. For example, the Emperor Commodus was assassinated in A. D. 192 as a part of the military got fed up when he started to act above the law, including the making of the gladiators deliberately losing to him in the Coliseum.
There was no drought in the run-up to Commodus’ murder’, but usually there is a drought prior to the murder of the emperor,” Christian said. “We’re not trying to claim that rainfall is the only explanation for all these things. It is just one of the many possible forcing variables that can ensure that this happens.”
The study is part of a growing field of study that examines how climate affected ancient societies, said Joseph Manning, a professor of Latin and Greek and history at Yale University, who was not involved in the new research. Last fall, Manning and his colleagues published a study in the journal Nature on how volcanic activity may have led to drier conditions that doomed the Ptolemaic dynasty in Egypt, Live Science reported earlier.
However, while the new study represents a “good basis” for the precipitation of the murder on the hypothesis of the researchers have a long way to go to support this idea, Manning said. For starters, it is relatively easy to search for a correlation between two things using statistics, he said. “They have some pretty good statistical work, but how do you know if you have the right mechanism?” [Photos: Gladiators of the Roman Empire]
In other words, the correlation does not equal causation, Manning said. But, given the promise of this preliminary research, it is worthwhile to dig into this hypothesis to determine whether the climate data actually jibe with the murder dates of the empire started in 27 B. C. to the end in A. D. 476, Manning said.
The hypothesis “sounds plausible,” said Jonathan Conant, associate professor of history at Brown University, who was not involved in the study. But while the rain may have played a role, as also other factors, Conant said. For example, most of Rome murders happened in the third century A. D. At this time, the Roman Empire had massive inflation, the outbreak of diseases and wars, all of which took a toll on the empire’s stability, Conant said.
“For me [the precipitation of the murder on the hypothesis] adds another layer of complexity and nuance to our understanding of the political history of the Roman Empire, especially in the third century,” Conant told Live Science.
The study is published in the October issue of the journal Economics Letters.
Original article on Live Science.