1). Slavery was ended by the Catholic church in Europe in about the 6th-7th century, over the great objections of the rich. Augustine once thundered that all slavery was “sin”. So, at the end of late antiquity/the beginning of the Middle Ages, slavery existed only in the fringes of Europe, in pagan areas, in all of Islam, and, horribly, even in the Eastern empire. But in Europe it was gone.
- Human rights as a concept was developed by the Catholic church in the late Middle Ages. in Spain, although many ideas about human rights were slowly being developed throughout the Middle Ages.
- Enlightenment philosophers, - all of them viciously anti Catholic - have argued that serfs might have been slaves. . Nonsense. Slaves were pieces of property, and the rich owned you utterly. It appears most slaves in the Roman empire were sexually and physically abused. The rich made lots of money by taking their little boy and female slaves and shoving them into a nearby brothel until they no longer were of interest to men. (The little boys were no longer of interest once they sprouted their first body hair, the girls when they lost their looks. Yes, it really was that awful.)
If you were an elderly or ill and possibly dying slave, you were condemned to an area where you were abandoned, without food, without care, until you died or recovered, If you recovered, you were reclaimed as a slave by your owner. Yes, I know that was not what Seneca, perhaps the biggest hypocrite ever born, said, but that’s what usually happened.
Serfs could marry, leave their master to go to another, earn money from an area they cleared and farmed, and, in a hundred other ways, live a decent life. This varied a lot of course, in different centuries and in different countries.