Although mainly inhabited by Armenians, Nagorno-Karabakh was awarded to the Azeri SSR after the Soviet Union overran the Caucasus in the 1920s. Shortly before the collapse of the Soviet Union, the region declared its independence from Azerbaijan, leading to a war between Nagorno-Karabakh and Armenia on one side against Azerbaijan on the other side. A ceasefire was agreed on in 1994, but the conflict remains unsettled. The Nagorno-Karabakh Republic is de facto independent but not recognized by any UN member. In Armenian the region is also known as Artsakh, named after a province of the ancient Armenian kingdom.