And that is all because there "ain't such an animal" as some initial "Turkish ethnic origin" - it's a random mix of Lydians, Persians, Friesians, Skits, Bithinians, Kurds, Arabian, Caucasian and whoever else (even contemporary Greeks are exactly the same cocktail) all of them living together in Byzantium, most of them Christians till 12 century and barely within the Osman Empire (which was a direct issue of a sort of a "Civil war" on a religious base against the Empire) it occured that so-called concept "Turk", which I think should be applied to citizens of nowadays Turkey, but it won't be such a big deal to be applied (as a nickname) to Azerbaijanis as well ))