Marcus Aurelius is the second-century Roman emperor who in the movies The Fall of the Roman Empire (1964) and Gladiator (2000) is killed by his son Commodus. The official story was that the emperor died at age 58 of the plague in the midst of a battle against the German tribes north of the Danube River, but historians tend to suspect that 18-year-old Commodus had a hand in his demise--he was there, for one thing, he had a motive, and he behaved pretty suspiciously in the aftermath of his father's death. (By the way, the real Commodus, reportedly every bit as wacky and obsessed with gladiators as Joaquin Phoenix, did not die in the arena at the hands of Russell Crowe--or Stephen Boyd. His twelve-year reign ended when a wrestler named Narcissus killed him in his bath, part of a conspiracy involving Commodus' close advisers--not a bad way to go, actually ... in a bathtub with a wrestler.)
In addition to being the emperor, Marcus Aurelius was a stoic philosopher, as which, interestingly, he is better remembered today than as emperor. His collection of philosophical meditations is still read, from which I gathered these two quotations, which I paraphrase:
"Living is more like wrestling than dancing because man can not study his moves or methods in advance. He has to stand up against whatever chance brings his way and adjust his actions to unpredictable circumstances."
"We have to practice our philosophy like those who wrestle and box in the arena, not like the gladiators. If a gladiator loses grasp of his weapon, he is killed on the spot. But if we have made our arms and legs our weapons, so that we draw only on the resources within ourselves, all we need to do is keep moving."