The standard definition of “definiteness” usually states that a “definite” noun is one whose referent is identifiable by the reader/hearer, either because it has been mentioned previously in the discourse or because it is accessible by context and shared understanding, etc. How languages use definite articles and other types of markers is complex and interesting, but most people working with definiteness tend to agree on one thing: proper nouns are inherently definite.
However, humans are creative and language is flexible. Thus in my last post, I said “there are kings in Mesopotamia: Bob, Joe, and Larry.” What is interesting about this sentence is that I have used proper names generically. There were no kings in Mesopotamia named Bob, Joe, or Larry, thus these PN’s have no specific referent. To make my point, the names of the kings were not important, only the idea that there were distinct kings. Bob, Joe, and Larry are placeholders for actual kings. So, are these PN’s definite or not? We do the same thing with geographic names. If my son repeatedly asks me where we are going, I will respond “Timbuktu”. In some Akkadian texts we read last semester, it seems as if mat Hana “the land of Hana” is being used in the same way, referring generally to the West, but not to any specific area.
So be careful, proper names aren’t always “definite”.