The exact origin of the Kurds has not been yet been researched, even though they have an ancient history. The Kurds reside mainly in Kurdestan. It is a large territory extending to a major part of the mountainous region of southeast Turkey, northeast Iraq, northwest Iran and parts of Russia, as well as Syria.
Up until 1914, the Kurds and Kurdestan were divided among Iran, Russia and the Ottoman Empire. Under a treaty concluded between the Soviet Union and Turkey in 1921, the Kurdish-inhabited region of the Caucasus was annexed to the Ottoman Empire. Subsequently, a part of Kurdestan was placed under Iraqi and Syrian rule when the Mosul region was annexed to Iraq.
In Iran, the Kurds mainly reside in Kurdestan, Kermanshahan, and south of the Western Azarbaijan province. In 1600, a number of the Kurds were forced to settle in the north of Khorasan province, at Quchan and Bojnourd, by the Safavid King, Shah Abbas; they still reside there today.
The Kurds are of Iranian origin. Their language is a North-West Iranian language of the Indo-European family of languages and have several dialects. The two Goorani (southern Kurdish) and Zaza (western Kurdish) dialects are vastly different from Kormanji (pure Kurdish). The dialects spoken in Sanandaj, Kermanshahan, and Suleimania (Iraq) are variations of Kormanji. The Kurds' struggle for autonomy and independence dates back to the 19th century, when they were under the Ottoman Empire. Iranian Kurds also rebelled against the central government in 1880.
In 1946, the People's Republic of Kurdestan, led by Qazi Mohammad, was established in Iranian Kurdestan, with Mahabad as its capital. The Iranian army crushed the republic when the Red Army pulled out of Iran in the same year.
There are several Kurdish clans. The significant ones are Mokri in the north of Kurdestan, Bani-Ardalan to their south (with Sanandaj as their center), Jaaf in southern and Kalhor in southernmost Kurdestan at the border with Kermanshahan.
Most Kurds are Sunnis of the Shafe'i, and some are followers of Yazidi and Ahl-e Haq sects, but Qaderi and Naqshbandi brands of Sufism are also common in some parts of the Iranian Kurdestan, particularly in its southern regions. The Kurdish population is estimated to be around 1.5 million.