h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've read that the Romans had a big problem with succession of power. The death (or assassination) of an emperor typically led to chaos, civil war, etc. So we learned that an orderly succession is in order, like when Clinton had to leave, Gore and Bush ... OK, never mind.

of course the Roman Republic managed quite nicely for a couple of centuries
what caused its downfall, acquisition of an Empire

Yes, another thing the Romans taught the world, avoid empire building. Good thing they put that idea to rest, huh?

There were a lot of problems early on, certainly. Augustus went through about 5 supposed heirs, who all died. In the second century, there was a process of not passing the throne on to the son of the Emperor, but to a worthy citizen, which worked well until Marcus Aurelius passed it to his son Commodus who was a bit mad. Later there was a period where everyone who became Emperor was murdered.

But prior to Augustus when Rome was a republic there was a period of stability until they won the Punic Wars and acquired an Empire. Then the politicians started fighting over the spoils resulting in the Social and Civil Wars and eventually in Augustus. A lesson there for imperialistic aggressive Republics everywhere ?

Juluis Caeser predated Augustus and there was a bit of turmoil after he was chopped down - a Civil War in fact.

The civil wars pre-dated Julius. Sulla and Marius took it in turns to take the reigns and plunge daggers in each others' supporters. When both of them were dead Julius formed a power bloc with the best soldier of the day (allegedly), Pompey, to threaten every other contender for power and a rich guy, Crassus (if I remember correctly) to bankroll the whole coup d'etat.

Then, when that broke down, he beat Pompey in battle and took sole control. Compared to that, the little fracas between Octavius/Augustus and Mark Anthony after Julius' death was piffling.

I heard in a lecture that Sulla, for all his dictatorial methods, was one of the few to simply decide to retire. He reportedly lived simply in the country, writing his memoirs and eventually dying in his sleep. Maybe he got a lucrative book deal like Clinton?

He obviously didn't know Michael Corleone. Do they qualify as something the Romans did?

Diocletian retired and managed to stay out of the fray for most of a decade. Then there came the reign of the multiple Caesars. Rome had become a backwater under Diocletian, who only visited it twice after his acension. The currency was so watered down that people hoarded any real money and resorted to barter.
Then came our little friend Constantine...
Who tortured his captured enemies, slaughtered his peers and murdered part of his own family, including his father-in-law.