Nazi Germany did to Europe what Europe did to the world

You're not really a slave if I can find someone in a worse situation than you.

Just because the English Royal Family had unpaid lackeys held in perpetual bondage and servants living hand-to-mouth on a meager dole that the royals could snatch back on a whim doesn't make them slaves. Just look at the treatment of Congolese miners under King Leopold. See? That's way worse. So outside of this once niche place and time, slavery really hasn't ever existed. And even then, I think its worth noting how those savages probably deserved it.