Explanation: The Roman Emperor Vitellius, during the Year of Four Emperors, roused the legions on the Rhine to oppose the Emperor Galba. No real reason or offense, he just felt like he could seize power. Galba was assassinated before his forces reached Rome, and the usurper Emperor Otho (it was an eventful year, hence the name) had his forces defeated by Vitellius, and committed suicide.

Vitellius proceeded to reign for a total of eight months, which he spent most of feasting and wasting money prodigiously. For this reason, amongst others, he was scorned by the general population of the city of Rome.

When the general Vespasian, a seasoned soldier who had sworn allegiance to Galba, and managed to get most of the eastern half of the Empire on his side, came marching along, Vitellius attempted to do what any brave Emperor who came to power on the backs of his loyal and noble legionaries would do!

… he attempted to surrender and abdicate.

The Praetorian Guard, having betrayed three (3) previous Emperors, knowing that their very-lucrative careers were done for if Vespasian won, made it very clear to Vitellius that surrender was not an option, and that, one way or another, Vitellius was going to either win or die as an emperor. Hint hint, get the (dagger’s) point?

Vitellius did not win.

The Roman crowds would heap abuse and throw garbage at him all the way through the city as he was paraded to his death like a common criminal.

And sure enough, the Praetorian suspicions were correct - Vespasian was not nearly stupid enough to keep the old Praetorians around, and had them replaced with loyal veterans from his own legions.