Azerbaijan is a country in the Caucasus region of Eurasia. It is bounded by Caspian Sea to the east, Russia's Daghestan region to the north, Georgia to the north-west, Armenia and Turkey to the south-west, and Iran to the south. Azerbaijan is a home to various ethnicities, majority of which are Azerbaijani, a Turkic ethnic group which numbers close to 10 million in the independent Republic of Azerbaijan.
During Median and Persian rule, many Caucasian Albanians adopted Zoroastrianism and then switched to Christianity prior to coming of Muslim Arabs and more importantly Muslim Turks. The Turkic tribes are believed to have arrived as small bands of ghazis whose conquests led to the Turkification of the population as largely native Caucasian and Iranian tribes adopted the Turkic language of the Oghuz and converted to Islam over a period of several hundred years.