Shocks to military support and subsequent assassinations in Ancient Rome

A dictator relies on his military's support; shocks to this support can threaten his rule. Motivated by this, we find that lower rainfall, along the north-eastern Roman Empire, predicts more assassinations of Roman emperors. Our proposed mechanism is as follows: lower precipitation increases the probability that Roman troops, who relied on local food supplies, starve. This pushes soldiers to mutiny, hence weakening the emperor's support, and increasing the probability he is assassinated.