The last retreat of the Hurri

The "Hurrian" language, associated with the Biblical Horites, comes up in the northern foothills of the Mesopotamia as of the first Bronze Age tablets from the region. Those foothills receive further witness from their northwest, in the "Hittite" age. By then, they are a mixed group speaking both Hurrian and Luwian. In the Iron Age the local monuments are Luwian or bilingual... with Aramaic. The Bible remembers "Horites" but as an ethnonym.

I don't think Hurrian is spoken anywhere during the Iron Age, but Urartu around Lake Van was speaking a cousin-language. Still: Hurrian history was not a simple tale of decline; they spread influence among the Hittites to the west, and (albeit under Aryan leadership) the Mitanni empire had a Hurri base when it conquered Mesopotamia.

One of those mixed regions, which went Luwian, is Kizzuwadna. There was an open question on whether it was Hurri first or Luwian.

Vladimir Shelestin has answered that, in "The ethnical history of Kizzuwatna: an onomastic approach". That is: place-names, which by the way trend conservative (witness: "Massachusetts"). Shelestin sees the first-attested placenames there to be Hurri. Luwian names spread in the province later, over the years of Hittite domination. In later years the Hittite elite became quite bilingual, in their own Luwian-related Knesian language and also in Luwian itself.

I am unsurprised, given the total absence of Luwian in the Mesopotamian record until the Late Bronze. The Song of Release composed in Hurri ~1600 BC, for fallen Ebla, may well be the first witness to Luwian words: vanishingly few. But onomastics are valuable evidence in support. Incidentally we only have elite-speak in Kizzuwadna's monuments; the merchants trended Aramaic and, subsequently, Greek. So who knows how long the "Horite" pagans were holding on.

Luwian looks like a southwest dialect, where we will later find its dialects Lycian and Carian. As for the Hurrian homeland, that is looking like immediately west and southwest of Lake Van.

Urartian, in this case, hailed from east and north. No Bronze Age source documented that region as far as I know, but more excavation at Lake Van may correct that.

UPDATE 3/19: Also, Kizzuwadna sorceresses. When they incanted in Horite, they incanted it clean; when they incanted Luwian, they incanted it with Hurri loanwords.