Armenia, officially the Republic of Armenia, is a country in the South Caucasus region of Eurasia. It is bordered by Turkey, Georgia, the Republic of Artsakh, Azerbaijan, and Iran. The country boasts great historical and cultural heritage: the Kingdom of Armenia reached its height under Tigranes the Great in the first century BCE and was the first state to adopt Christianity as its official religion in the year 301 BCE. Between the sixteenth and nineteenth centuries, Armenia was repeatedly ruled by Ottoman and Iranian empires. The Armenian Genocide occurred during World War I, which was the systematic extermination of 1.5 million Armenians by the Ottoman government. After the Russian Revolution, Armenia became a part of the Transcaucasian Socialist Federative Soviet Republic, and then a founding member of the Soviet Union. Following the dissolution of the Soviet Union, the Republic of Armenia became independent in 1991.