There’s no definitive formula for making a memorable movie villain. Some are made compelling by a particularly magnetic performance, and some are just so soundly written that they breathe life into the story they inhabit. Some movie villains just make a very good point, and it’s very hard to deny an antagonist who speaks sense.

What’s clear is that all good villains come from somewhere. Though many stem from some manner of fear – either in an obvious way or in a more metaphorical or societal sense – some of the best movie villains are actually real. That thought alone is pretty scary, but do you know what’s worse? That you didn’t even know it.

There is actually a wealth of brilliant movie villains that have been plucked straight out of history and dropped in the middle of a blockbuster. Some of these are relatively obvious, but there are some that somehow flew under the radar. Most of them worked so brilliantly within their respective movies that you simply didn’t know they were real – don’t worry though, they can’t hurt you. (At least, not anymore.)

8. Commodus – Gladiator

Joaquin Phoenix as Commodus in Gladiator

Played by the always incredible Joaquin Phoenix, Gladiator‘s antagonist Commodus is one of cinema’s most memorable villains. The depraved and sadistic Commodus is a hedonistic egomaniac, acting truly unhinged on numerous occasions throughout the movie, putting him at odds with former general Maximus (Russell Crowe). However, though he’s a particularly excellent movie villain, what many film fans may not have known is that Commodus was actually a real Roman emperor.

Commodus ruled from 177 AD to 192 AD, giving him a reign of 15 years, but for the first three years (177-180), he ruled jointly with his father, Marcus Aurelius (played in Gladiator by Richard Harris). Commodus was a more peaceful ruler than his father, but his reign ultimately saw the beginning of a great deal of political turmoil in the Roman empire. He was eventually assassinated in the bath by a wrestler (yes, really).

The differences between the real Commodus and the version seen in Gladiator are debatable. Some believe that the movie played fast and loose with history, while others believe it to be a relatively accurate depiction of the emperor’s later years, which saw him descend into increasingly dictatorial ways. Regardless, the stamp Joaquin Phoenix’s Commodus left on the movie world is far more memorable to modern society than the acts of the actual man himself, meaning that some didn’t know he was a real emperor at all.