The Nagorno-Karabakh Republic (NKR)  (Armenian: Լեռնային Ղարաբաղ Հանրապետություն Lernayin Gharabaghi Hanrapetut’yun) or Artsakh Republic is a de facto independent republic in the Nagorno-Karabakh region of the South Caucasus.
The mostly Armenian-populated region of Nagorno-Karabakh firstly became disputed between Armenia and Azerbaijan in 1918. After the Soviet Union established control over the area, in 1923 it formed the Nagorno-Karabakh Autonomous Oblast (NKAO) within the Azerbaijan SSR. In the final years of the Soviet Union, the region again became a source of dispute between Armenia and Azerbaijan, culminating in the Nagorno-Karabakh War of 1988-1994.
On December 10 1991, a referendum held in the NKAO and the neighboring Shahumian region resulted in a declaration of independence from Azerbaijan as the Nagorno-Karabakh Republic. The country remains unrecognized by any international organization or country, including Armenia. Representatives of the governments of Armenia and Azerbaijan have since been holding peace talks mediated by the OSCE Minsk Group.