Today′s Azerbaijani languages evolved from the Eastern Oghuz branch of Western (Oghuz) Turkic[11] which spread to Southwestern Asia during medieval Turkic migrations, and has been heavily influenced by Persian.[12] Arabic also influenced the language, but Arabic words were mainly transmitted through the intermediary of literary Persian.[13]
Azerbaijani gradually supplanted the Iranian languages in what is now northern Iran (most notably the Tat, Azari, and Middle Persian varieties), and a variety of Caucasian languages in the Caucasus, particularly Udi. By the beginning of the 16th century, it had become the dominant language of the region, and was a spoken language in the court of the Safavid Empire. However, minorities in both Azerbaijan and Iran continue to speak the earlier Iranian languages to this day, and Middle- and Modern Persian loanwords are numerous in the Azerbaijani language.
The historical development of Azerbaijani can be divided into two major periods: early (c. 16th to 18th century) and modern (18th century to present). Azerbaijani differs from its descendant in that it contained a much greater amount of Persian, and Arabic loanwords, phrases and syntactic elements. Early writings in Azerbaijani also demonstrate linguistic interchangeability between Oghuz and Kypchak elements in many aspects (such as pronouns, case endings, participles, etc.). As Azerbaijani gradually moved from being merely a language of epic and lyric poetry to being also a language of journalism and scientific research, its literary version has become more or less unified and simplified with the loss of many archaic Turkic elements, stilted Iranisms and Ottomanisms, and other words, expressions, and rules that failed to gain popularity among Azerbaijani-speaking masses.
