Yes, their history is v. interesting, often tragic and highly revealing of the nature of the societies they live/d in. A good book on the subject is 'Another Darkness, Another Dawn' by Becky Taylor, though you might struggle to find it for less than £20. Google preview: https://books.google.co.uk/books?id=sgowBQAAQBAJ&printsec=frontcover#v=onepage&q&f=false