They are thought to either be descended from original settlers of the Caucasus (North and/or South) or supposedly Nakh-speaking ethnic minorities in the north-eastern regions of the ancient state of Urartu (whose people also spoke a language that was possibly related to the Nakh languages). The two theories are not mutually incompatible, and there has been much evidence that seems to link the two (either by dual origins or the "return" theory, in which the Nakh peoples originally lived in the Caucasus, migrated down to the south, lived there for a long period of time, and then returned to the Caucasus).