Riots began in Nagorno-Karabakh as early as 1988, and a full-scale war broke out between Azerbaijan and Armenia between 1991 and 1994.
Up to 30,000 people lost their lives and over a million were forced to flee.
A ceasefire was signed in 1994, but the conflict itself was never resolved.
Now both countries have upgraded and it is feared that it could lead to another war.
At the same time, the people of Nagorno-Karabakh want to be independent and have declared themselves their own state, but which is not recognized by anyone.