That interesting question attracted my attention one day while I was reading various ancient history articles and writings online. I’ve asked myself: “Did they really get assassinated so often or that was quite “normal” ratio of killings, given the fact that was the Great Roman Empire?"
In her analysis, Dr. Emma Southon includes a lecture held by the Stanford historian Walter Schreidel who compares the Romans and their average length of reign ( as well as the cases of a violent death) to thirty one different historical dynasties.
According to Schreidel, the Romans were, in fact, incredibly unstable monarchy.
On the one hand, the average reign length for the best times of the Roman Empire (Augustus to Theodosius) was 7 years. A number, it appears, half as long as the global average.
On the other hand, the longest Roman dynasty, the Julio-Claudians who run for about 100 years and last about 4 generations was far below the global average dynasty length of 300 years and 10 generations.
For the Romans, Dr Emma Southon says, that is about as good as it gets. If at any stage in Roman history you can get three emperors in a row who don’t get murdered, that’s a winning streak. The absolute record is six in a row from Nerva to Marcus Aurelius and that’s because all those emperors adopted their successor. As soon as Marcus A let his biological son get in on the ruling act, we got Commodus who actually ruled for 15 years but is mainly remembered for being a berk and getting killed.
So the Romans ARE odd in terms of how unstable and violent their monarchy was.
If you want to read the whole analysis, you can find it here.
I strongly recommend you to have a look at it. Interesting numbers emerge, as well as exciting conclusions!