Persia and Ottoman Turkey divided Armenia into eastern and western portions between the 16th and 18th centuries. Russia took over Persia's holdings in 1828. During World War I, Ottoman Turkey carried out forced resettlement and other harsh policies against Armenians that resulted in up to 1.5 million deaths. This national genocide remains a contentious issue in Armenian-Turkish relations.
Armenia declared its independence in 1918, following the Russian revolution. The Bolshevik army regained control of Armenia two years later, and it was named part of a Transcaucasian Soviet Federated Socialist Republic in 1922. Armenia became a separate union republic within the Soviet system from 1936 until its collapse in 1991. A referendum on independence was held on 21 September 1991. It was approved by 99% of the voters, and independence was declared two days later.
Beginning in 1988, conflict engulfed Nagorno-Karabakh (NK), an enclave within neighboring Azerbaijan, populated largely by ethnic Armenians. The legislature of NK has called for unification with Armenia, while Azerbaijan has resisted the secession of its enclave. Emigration of 350,000 Armenians residing in Azerbaijan and over one million Azerbaijanis residing in Armenia followed conflict in both states. In 1993, Armenian forces gained control over NK, occupying 20% of Azerbaijani territory. A ceasefire has held fitfully since May 1994, but talks on a political settlement remain inconclusive.