History Memes

Assuming the first person is working through it in chronological order and hasn't reached that realisation yet, they've probably just encountered the first such instance. Given that Tiberius was alleged by some to have been smothered by the head of the Pretorian Guard, I assume that's who they're talking about.

To expand on "a lot":

Tiberius was the second Emperor, succeeded by Calilgula who was also killed by Pretorians four years later. The third (Claudius) died of other causes, the fourth (Nero) was merely abandoned by the guard, but the fifth (Galba) was once again murdered by Pretorian soldiers. Within the first hundred years of the Imperial period, three out of seven were actively killed by the guard and one was deserted, so I'll score this as 3.5/7.

Vespasian and Titus died non-violently, but Domitian was once again murdered, with at least one Pretorian officer apparently aware of the plot, which I'll mark as "deserted"; 4/10.

Six more died naturally (Nerva, Trajan, Hadrian, Antonius Pius, Marcus Aurelius, Lucius Verus), but with the seventeenth, they bucked again: Commodus and Pertinax were killed by the guard, Didius Julianus got ghosted again. Tally: 7.5/20 so far, 6 of them direct murder.

Geta died by fratricide. His brother and murderer, Caracalla, was stabbed by a soldier, instigated by the Pretorian Prefect then finished off by Pretorian Tribunes. That same prefect and next emperor, Macrinus, actually had the loyalty of his man, so Elagabalus had to usurp the hard way. In turn, he was again killed by the guard. We're at 9.5/24, 8 direct murders.

Severus Alexander, Maximinus I, Gordian I and II died in the "normal" infighting of the Crisis of the Third Century, Pupienus and Balbinus were each murdered by the guard again. Score is 11.5/30, 10 direct, holding the average of a third of all emperors being killed by the Guard.

I gotta go now, but so far we're 265 years into the Imperial era, 30 Emperors deep and a solid third of them died by the hand of the Guard.