> Slaves actually called slaves where relatively uncommon in history.

I really don’t think this is true. Human property varied in how common it was but the institution existed in every agricultural society I’m aware of up until at least three 1600s when serfdom died out in England. That’s probably the first society in which humans were not held as property. Western Europe was also likely the first agricultural society not to have chattel slavery but I’m less confident. Certainly slavery was practiced in the Moslem world into the 1900s and well attested all over Asia and in most of Africa and the Americas.

when serfdom died out in England You’re equating serfdom with slavery when my point is separating slavery by name excludes such classes. India and China for example where very stratified societies, but slavery was effectively a separate and less common institution. https://en.wikipedia.org/wiki/Slavery_in_China

https://en.wikipedia.org/wiki/Slavery_in_India

Anyway, by relatively uncommon I mean compared to the US concept of slavery where they made up a huge chunk of the southern workforce and could be sold between individuals.

The third servile war was hardly successful. They all ended up literally crucified.