[4] The Azerbaijani are of mixed ethnic origin, the oldest element deriving from the indigenous population of eastern Transcaucasia and possibly from the Medians of northern Persia.
There is evidence that, due to repeated invasions and migrations, aboriginal Caucasians were culturally assimilated, first by Iranians, such as the Alans, and later by the Oghuz Turks.
Considerable information has been learned about the Caucasian Albanians including their language, history, early conversion to Christianity, and close ties to the Armenians.
During the period of its existence in the early 1st millennium BCE, Mannai was surrounded by three major powers: Assyria, Urartu, and Media.
[8] The conclusion from the testing shows that Azerbaijani Turks of the republic are a mixed population with relationships, in order of greatest similarity, with the Caucasus, Iranians and Near Easterners, Europeans, and Turkmen.
[12] Azerbaijani Turks, however, are still demonstrated to possess significant genetic influences from East Asia relative to their non-Turkic neighbors.
It is supported by historical accounts, by the existence of the Old Azari language, present-day place names, cultural similarities between Iranian peoples and Azerbaijanis, and archaeological and ethnical evidence.
According to Vladimir Minorsky, around the 9th and 10th centuries:"The original sedentary population of Azarbayjan consisted of a mass of peasants and at the time of the Arab conquest was compromised under the semi-contemptuous term of Uluj ("non-Arab")-somewhat similar to the raya (*ri’aya) of the Ottoman empire.
They spoke a number of dialects (Adhari(Azari), Talishi) of which even now there remains some islets surviving amidst the Turkish speaking population.
[16] Ebn al-Moqaffa' (d. 142/759) is quoted by ibn Al-Nadim in his famous Al-Fihrist as stating that Azerbaijan, Nahavand, Rayy, Hamadan and Esfahan speak Pahlavi (Fahlavi) and collectively constitute the region of Fahlah.
Hamzeh Isfahani writes in the book Al-Tanbih 'ala Hoduth alTashif that five "tongues" or dialects, were common in Sassanian Iran: Pahlavi (Fahlavi), Dari, Parsi (Farsi), Khuzi and Soryani.
Khuzi is associated with the cities of Khuzistan where kings and dignitaries used it in private conversation and during leisure time, in the bath houses for instance.
Also, the Brockhaus and Efron Encyclopedic Dictionary, published in 1890, writes that Azerbaijani's are only linguistically Turkic and Iranians by race.
[26]According to Professor Xavier De Planhol: Azeri material culture, a result of this multi-secular symbiosis, is thus a subtle combination of indigenous elements and nomadic contributions, but the ratio between them remains to be determined.
The few researches undertaken (Planhol, 1960) demonstrate the indisputable predominance of Iranian tradition in agricultural techniques (irrigation, rotation systems, terraced cultivation) and in several settlement traits (winter troglodytism of people and livestock, evident in the widespread underground stables).
The large villages of Iranian peasants in the irrigated valleys have worked as points for crystallization of the newcomers even in the course of linguistic transformation; these places have preserved their sites and transmitted their knowledge.
The toponymy, with more than half of the place names of Iranian origin in some areas, such as the Sahand, a huge volcanic massif south of Tabriz, or the Qara Dagh, near the border (Planhol, 1966, p. 305; Bazin, 1982, p. 28) bears witness to this continuity.
[29] The terms "Azeri" and "Azerbaijani" were born only in the 20th century upon the formation of the short-lived Republic of Azerbaijan in 1918, prior to which they were referred to as Tatars.
It was noted that studies on genetic distances based on both HLA allele and class II haplotype frequencies "place Azerbaijani sample in the Mediterranean cluster close to Kurds, Gorgan, Chuvash (South Russia, towards North Caucasus), Iranians and Caucasian populations (Svan and Georgians)".
The study further showed that the Azerbaijanis are "close to Iranian populations like Baloch and Iranians from Yazd, Gorgan Turkmen and Kurds (the closest population according to plain genetic distances), but in a half-way position between Mediterraneans and Western and Central Siberians, such as Mansi or Todja, together with Gorgan, Kurds and Chuvash (South Russian towards North Caucasus)."
[citation needed] According to generalized data from various laboratories, more than half of Azerbaijanis are carriers of Y-haplogroups of Near East origin (E-M35, G-P15, J-P209 and T-CTS6507), which confirms the hypothesis of Neolithic migrations from the Fertile Crescent.
East European subclades of the Y-haplogroup R (R-Z2109, R-PF7562, R-Y4364) and haplogroups of Central Asian origin (C-M217, N-P43, O-F238, Q-M242, R-Z93, R-M478) totally cover more than a third of the studied and indicate migrations from eastern and northeastern geographical areas.
There is evidence of limited genetic admixture derived from Central Asians (specifically Haplogroup H12), notably the Turkmen, which is higher than that of their neighbors, the Georgians and Armenians.
[8] The conclusion from the testing shows that the Azerbaijanis are a mixed population with relationships, in order of greatest similarity, with the Caucasus, Iranians and Near Easterners, Europeans, and Turkmen.
[42] Ibn al-Athir, an Arab historian, declared that the Oghuz Turks had come to Transoxiana in the period of the caliph Al-Mahdi in the years between 775 and 785.
The Southwestern Turkic dialects gradually supplanted the Tat, Azari, and Middle Persian dialects in northern Iran, and a variety of Caucasian languages in the Caucasus, particularly Udi, and had become the dominant during the High to Late Medieval period, under the rule of the Aq Qoyunlu and Qara Qoyunlu (14th to 15th centuries), the process of Turkification being mostly complete by the Safavid period (16th century).