Iranian Azerbaijan is the land originally and historically called Azerbaijan; the Azerbaijani-populated Republic of Azerbaijan appropriated the name of the neighbouring Azerbaijani-populated region in Iran during the 20th century.[6][7][8] Historic Azerbaijan was called Atropatene in antiquity and Aturpatakan (Adurbadagan) in the pre-Islamic Middle Ages. Some people refer to Iranian Azerbaijan as South (or Southern) Azerbaijan and the Republic of Azerbaijan as Northern Azerbaijan,[9] although others believe that these terms are irredentist and politically motivated.[10][11][12]
Following military defeats at the hands of the Russian Empire, Qajar Persia ceded all of its territories in the North Caucasus and Transcaucasia to Russia via the Treaty of Gulistan of 1813 and the Treaty of Turkmenchay of 1828.[13] The territories south of the Aras River, which comprised the region historically known as Azerbaijan, became the new north-west frontier of the Persian Empire and later Iran.[14] The territories north of the Aras River, which were not known by the name Azerbaijan at the time of their capture by Russia, were absorbed into the Russian Empire, renamed the Azerbaijan Democratic Republic during the country's short-lived independence from 1918 to 1920,[15] incorporated into the Soviet Union as the Azerbaijan Soviet Socialist Republic, and finally became the independent Republic of Azerbaijan when the Soviet Union dissolved.
^James Minahan. "Miniature Empires", Published by Greenwood Publishing Group, 1998.
^The Encyclopaedia of Islam, Volume XI (Brill Publishers, Leiden, 2002). Article: "Zandjan", page 446:
The mediaeval geographers mostly placed Zandjan in Djibal province, usually linking it with Abhar [q.v] or Awhar some 80 km/50 miles to its south-east, but they usually stated that it was on the frontier with Adharbaydjan, and some authorities attributed it to Daylam or to Rayy.
^Rezvani, Babak (2014). Ethno-territorial conflict and coexistence in the caucasus, Central Asia and Fereydan: academisch proefschrift. Amsterdam: Amsterdam University Press. p. 356. ISBN978-9048519286. The region to the north of the river Araxes was not called Azerbaijan prior to 1918, unlike the region in northwestern Iran that has been called since so long ago.
^Michael P. Croissant, "The Armenia-Azerbaijan Conflict: Causes and Implications", Praeger/Greenwood, 1998. excerpt from pg 61: "During the Soviet-era historical revisionism and myth-building intended to denounce imperialism, the notion of a "northern" and "southern" Azerbaijan was created and propagated throughout USSR. It was charged that the "two Azerbaijanis" once united were separated artificially by a conspiracy between imperial Russia and Iran".
^Ethnic Conflict and International Security, Edited by Michael E. Brown, Princeton University Press, 1993
^Bert G. Fragner, ‘Soviet Nationalism’: An Ideological Legacy to the Independent Republics of Central Asia’ in Van Schendel, Willem (Editor). Identity Politics in Central Asia and the Muslim World: Nationalism, Ethnicity and Labour in the Twentieth Century. London, GBR: I. B. Tauris & Company, Limited, 2001. Excerpt from pg 24: "Under Soviet auspices and in accordance with Soviet nationalism, historical Azerbaijan proper was reinterpreted as 'Southern Azerbaijan', with demands for liberation and, eventually, for 're'-unification with Northern (Soviet) Azerbaijan – a breathtaking manipulation. No need to point to concrete Soviet political activities in this direction, as in 1945–46 etc. The really interesting point is that in the independent former Soviet republics this typically Soviet ideological pattern has long outlasted the Soviet Union."