I read something recently about supposed critiques and explorations of slavery in Shakespeare's plays and it struck me as odd- I don't think of slaves as existing in Elizabethan London (or really, England as a whole post-feudalism). If there were slaves, what race would they have been?
There were occasional enslaved Africans and Native Americans in Elizabethan England. It wasn't a huge number but it wasn't like it didn't exist....