http://en.wikipedia.org/wiki/Iranian_Azeris
 

Turning Points in the history of Azerbaijan:
From the formation of Persian Empire Azerbaijan was a part it. Azerbaijan was divided as a result of two wars between Russia & Persia:
 
        1813-Treaty of Gulistan, resulted in the separation of Baku, Shirvan, Shaki, Karabagh and part of
        Talysh
        1827-Tnreaty of Turkmanchay, it produced the border agreement as it is today

 
The separated parts stayed under Russian Empire, and then The Soviet. However
        1918-1920 Short period of independancy as the Democratic Republic of Azerbaijan

http://en.wikipedia.org/wiki/History_of_Azerbaijan
http://www.iranian.com/Opinion/2003/August/Azeri/

The articles below and their correspondence links will give you some ideas regarding the socio-political feelings of the Azeris in Iran.

http://www.iranian.com/Opinion/2002/August/Azeri/index.html
http://news.bbc.co.uk/1/hi/8516682.stm
http://iranminoritynews.org/wp-content/uploads/2009/04/iranian-azeris-a-giant-minority.pdf