It's still kind of disputed, that's why I left that out of the conversation.

Forgetting for a moment about the English term "slave", it's interesting that in Italian slaves are called "schiavi", with the singular "schiavo", while in old Romanian we used to called Slav people (who were different from us, Romance-speaking people) as "șchei", with the singular "șchiau/schiau", the second form at singular pretty similar to the independently formed "schiavo" from Italian (which means "slave", like I said).

And in Greek, we say "Σλάβος" (Slav) which is only one word away from "σκλάβος" (sclave) so I've always thought that the two were connected, until very recently, when I checked wikipedia just to be sure and found out that I was probably wrong.