Azerbaijan occupies the western ranges of the Greater and Lesser Caucasus and the Kura River valley. The republic includes the Nakhchivan Autonomous Republic (or Naxçivan, an exclave separated from Azerbaijan proper by Armenia) and Nagorno-Karabakh (an ethnically Armenian region that now has de facto independence; see under History ). The Azeri (Azerbaijani), a Turkic-speaking, Shiite Muslim people of Persian culture, make up about 90% of the republic's population; Dagestanis, Russians, and Armenians (largely in Nagorno-Karabakh) are the largest minorities; Azerbaijani (Azeri) is the country's official language. The republic's educational institutions include Bakı State Univ., Khazar Univ. and the Azerbaijan Academy of Sciences.