The region is referenced repeatedly by many Greek and Roman sources in the last century BC and the first centuries of the Christian era. Azerbaijanis in this northern kingdom were vassals of the Persians until the ninth century. During much of this time, the kingdom bore witness to successive waves of migrations of nomadic Turkish tribes, including the Huns and the Khazars. The Azerbaijani Turks today accept both these Turkish nomads and the Albanians as their ancestors.

By the ninth century, Albanian authority in the region began to wane, while the Persian Shirvan dynasty rose to power in eastern Caucasia. Its rule of the region had religious as well as political import. The Azerbaijani Turks adopted Shi’ism from the Persian Muslims, while the Ottoman Turks practiced Sunni Islam. The Shi’a Azerbaijanis were thus more closely tied to the Persian Shi’as than they were to fellow Sunni Turks. This caused difficulties during the 19th and 20th centuries, when Azerbaijani intellectuals tried to reunite the two Turkish strands, which shared a common language and culture but were divided by religion.

Succeeding centuries saw Azerbaijan ruled by a series of mainly Turkic empires from central Asia, a development that led to the turkification of the region. By the beginning of the 16th century, the Safavid dynasty of southern Azerbaijan assumed the throne in Persia and eventually incorporated the Shirvan kingdom, as well as Nakhichevan and Karabakh, into its rule. Wars between the Turkish Ottoman empire and the Safavid in this period, however, led to Ottoman occupation of eastern Caucasia, between 1578 and 1603.

The years 1700–20 were pivotal in Azerbaijani history, marking the beginning of Russian influence in the area, as Peter I (the Great) brought the Caspian coast under his control. With the breakup of the Safavid dynasty in the mid1700s, however, the remains of the empire fell not to the Russians, but to a number of independent, largely TurkicIslamic khanates, who fought with each other for control of the region.

During the reign of Catherine the Great (1762–96), Russia initiated a new cycle of expansionism, balanced against continued hostilities with the Ottoman Turks. Catherine turned her attention to the small khanates, or kingdoms, of northern Azerbaijan; Russian interest in this area alarmed the Persians more so than the Turks. Two Russo-Persian wars (1804– 13 and 1826–28) decided the matter in Russia’s favor. Henceforth, the Azerbaijani khanates north of the Araz River belonged to Russia, while those on the southern banks remain Iranian to the present day.

With the collapse of tsarist rule in Russia at the end of World War I, Azerbaijan— with Armenia and Georgia—declared independence on May 28, 1918, a day which is still celebrated today. The Democratic Republic of Azerbaijan, ruled by the Azerbaijani Muslim Democratic Party, or Mussavat, enjoyed popular support, particularly among the urban elite. When its important rural support base began to erode, however, and Russia gained strength under the Soviets, the Azerbaijani state was overthrown by the Bolsheviks, who seized power on April 28, 1920. With the Red Army occupying its territory, Azerbaijan was forcibly incorporated into the Soviet Union with the signing of the Treaty of Formation of the USSR on December 30, 1922.

"Cultural Handbook for the East European and Eurasian States" American Councils for International Eduction: ACTR/ACCELS, ed. Lisa A. Choate and Dan E. Davidson
http://www.americancouncils.org/pdfs/cultural_handbook_03.pdf