Rough Roman Memes

Explanation: Augustus's reign was filled to the brim with propaganda, which seeped through every aspect of the average Roman's life — politics, literature, coinage, imagery, and, of course, religion. The temple of Janus in Rome had its gates open in times of war and closed in times of peace and, as you can imagine, Romans being a very contentious people, they were open for most of their civilization's history. Well, Augustus made a big deal of closing the temple's gates in 29 BC (only the third time it was done up to that point that we know of), which I've seen proposed as one of the conventional beginnings of the Pax Romana/Pax Augusta (Roman Peace/Peace of Augustus). The Pax would last until the end of Marcus Aurelius's reign.

… Wait, does that mean that Rome was at peace for 200 years? Well, yes, but actually no. It wasn't at peace even during Augustus's reign, who had to close the damn gates two more times—in 25 BC and 13 BC, respectively. Can it be really considered a peaceful time if you keep interrupting it with war?

Of course, Augustus wanted the Pax to last, and he recognized that, for there to be peace, the empire needed stability and continuity, so he immediately set about finding a worthy heir. What could go wrong? Well, as it turns out, pretty much everything.

At first, he had high expectations for his sister's son, Marcellus, who died in 23 BC, and his second-in-command and son-in-law, Marcus Agrippa, who died in 12 BC; he then fixed his priorities on Agrippa's sons, Lucius and Gaius, who died in AD 2 and 4, respectively; he briefly considered Agrippa's third son, Agrippa Postumus, but then promptly banished him in AD 7 (he was later assassinated in unknown circumstances); luckily, Augustus also had two stepsons, Drusus and Tiberius. The former died in 9 BC, and the latter would eventually become emperor by virtue of being the only survivor of Uncle Gus's fetch quest.
Tiberius went on to become one of the most painfully milquetoast Roman emperors of them all (but that's a talk for another day), and he would also survive his own sons, Germanicus and Drusus, who died earlier than anticipated in AD 19 and 23, respectively. Golly, so many deaths so early in the empire's peaceful history! Some would say that the empire was doomed from the start, but not me! Roma Invicta!