[s1artibartfast]

Are we talking genetic ancestry? What if the genetic ancestors have little in common with the current geographic population What if the genetic ancestors themselves were brutal slavers and overlords who extracted the riches by force?

[TeaBrain]

This is a very good point, which I brought up in another comment. Arguing on the basis of broad genetic ancestry to establish ownership of ancient artifacts can quickly get murky and nonsensical, when considering nations that exist today with similar genetic ancestry, and also those former nations which may have been antagonistic, yet have similar genetics.