Roman emperors assassinated often

Ancient Rome was a dangerous place to be an emperor. During its run from 27 B.C. to its end in A.D. 476, about 20 percent of Rome's 82 emperors were assassinated while in power. So, what led to their downfall? Some are blaming the lack of rain. In drought there's more probability of assassinations as soldiers go hungry. Using ancient climate data, researchers analyzed thousands of fossilized tree rings from France and Germany and calculated how much it had rained there for the past 2,500 years. This area once comprised the Roman frontier, where military troops were stationed.

Many factors can lead to an assassination. Correlation does not equal causation.