After the fall of Russian Empire in 1918 , the South Caucasus region was unified into a single political entity twice : as Transcaucasian Democratic Federative Republic from 9 April 1918 to 26 May 1918 , and as Transcaucasian Socialist Federative Soviet Republic from 12 March 1922 to 5 December 1936 .
The region was combined togerther twice - during the Russian Civil War ( Transcaucasian Democratic Federative Republic ) from 9 April 1918 to 26 May 1918 , and under the Soviet rule ( Transcaucasian SFSR ) from 12 March 1922 to 5 December 1936 .