There has to be more, because in Europe, and particularly in southern europe there has been slavery for thousends of years. Everyone has been slave to everyone, like a free for all.

Yet there's no one making claims based on that, and I'm not aware that such claims existed in the past neither. People just accepted as a fact of life and moved on.

If you look at how all the relations played out between southern europe, the Ottoman empire and northen africa in general, you'll see this isn't from so distant past.