Azari or the Ancient Language of Azerbaijan
Azari or the Ancient Language of Azerbaijan is a treatise written by the Iranian scholar Ahmad Kasravi in 1925, about the history of Old Azeri. This book has been approved by orientalists. In this book, Kasravi, using numerous documents and manuscripts, argues that the Old Azeri language should not be categorized as a member of the Turkic languages, but as an Iranian language, a descendant of the Median language.
This treatise, which was Kasravi's first serious work, was very influential worldwide and led to a new theory in Iran about the existence of Iranian roots in the Azeri language.
In the words of the Encyclopædia Iranica:
Concept
Kasravi's motivation for writing the work was political. He published the work in a period of raging controversy among papers based in Iran, Istanbul and Baku on the Origin of the Azerbaijanis. Kasravi, after studying both arguments, concluded that the claims of the Turkish journalists were unfounded and non-academic, and the replies of the Iranian journalists were not "founded in a knowledge of history".In this book, Kasravi first proposed the theory that the language of the region of Azerbaijan in northwestern Iran was a language of the Iranian language family a few centuries prior to the Turkic domination in this region. According to historical evidence, he named this language Azeri. This book made Kasravi famous in Iranian studies circles and he became a member of scientific circles abroad. The first edition of the book, and consequently the processing of theory, was based only on historical contexts. Later, Kasravi studied linguistics and in later editions of the book, he also dealt with this theory according to its linguistic foundations.
Kasravi's research motivated researchers to search for the remains of that historical language in different parts of Azerbaijan and find other examples of this language. Iranica adds:
Kasravi's historical monuments have been recognized by other scholars. Vladimir Minorsky says about Kasravi: "Kasravi has the spirit of an honest historian. He is meticulous in detail and in presentation"