Wikipedia says this is a sirloin. I'll have to take their word for it.
I heard this one the other day and I had to rush home and look it up, because I'd never heard it before. To be fair, that may be because I don't really know a lot about meat or preparing it (not something I do much, being unable to digest it).
What is this myth? That the cut of beef called sirloin got its name because an English king once knighted a piece of meat and called it "Sir loin."
Sadly, as cute as the story is, it's not at all true.
It's French. "Sir Loin" is actually "sur longe" ... Longe was French for loin, and sur simply means "above." So it is literally the cut "above the loin." *
Where is that? Well, that depends on where you live.
If you're American, it's this lime green spot:
If you're British, it's practically a quarter of the cow:
If you're Dutch, it's this long peach colored area:
And if you're Brazilian, it's a slim area between the tenderloin and it's skirt (and your cows have this funny hump too):