On August 23, 1990, the then Armenian SSR Supreme Council (Parliament) adopted the Declaration of Independence of Armenia.

The Declaration of Independence was based on the December 1, 1989 joint decision by the Armenian SSR Supreme Council and the Nagorno-Karabakh National Council on the “Reunification of the Armenian SSR and the Mountainous Region of Karabakh.”

And on September 21, 1991, a referendum on independence was held in Armenia.