Original: The region was unified as a single political entity 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.
Simplified: 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.