I was very curious and doing some study. Any help is appreciated!
When slavery was big in the world(mainly a time frame from Ancient Greece and Rome(or earlier) to the Middle Ages Era, to give a time frame), was everyone considered a possible slave to the Romans? What stopped a normal(but poor)citizen from just being grabbed by the slavers? How were common slaves not confused for common citizens ? And was every foreigner considered a slave(for example, a ship from Gaul pulls into harbour in a city where buying and selling slaves is prevalent, would they just be grabbed up as chattel immediately because they were not Roman and thus easy prey?)
What about traders from different lands, what kept the Romans, Persians or others from just arresting them and taking them as slaves? Were slaves just taken as prisoners of war, or were they sometimes just nabbed on a whim?
Were slaves only ever used as servants, gladiators, sex slaves and such? Or could they rise higher up and become trusted members of a family? Why and how? What made people decide to make eunuchs or such? Did they ever trust slaves enough to make them their guards?
If a slave was taken as a prisoner against their will and were former fighters, soldiers, etc; what kept them from just trying to immediately murder their masters and make a break for it? Was it just fear of being whipped? Death? Crippling? I know about Spartacus's famous uprising and such, but what stopped many others from doing the same thing?
What brought about the end of slavery? How was it policed?Was it prevalent in the Middle Ages still, or did it disappear until American slavery took over before the civil war?
I'm guessing this is for schoolwork, or at least something like it, so I'm going to give you two sources on Roman eunuchs. First, an essay on Roman eunuchs from 1995 in JStor, which should get you enough for a solid citation in any college paper. If you are very keen, chapter 6 of this book is specifically on eunuchs and solid reading. A broad view of late Roman era slavery can be found in the seminal Origins of the European Economy, don't let the title scare you off, for a large part of the economy was slavery. Eunuchs are included in the discussion but it should prove interesting to your studies more broadly.
Hiya!
So, the body of your post solely discusses slavery in Rome, which is fine - we'd ask, however, that responses also focus solely on slavery in Rome, as spreading the discussion to the middle-ages (an extra thousand years of European history) is too-wide-a-scope for /r/AskHistorians.
Thanks for your understanding!