Zeleny Klyn (Green Ukraine), is a historical Ukrainian name for the land in the Russian Far East area between the Amur River and the Pacific Ocean.
After the Russian Revolution of 1917, the Ukrainian Republic of the Far East was a projected country in the Russian Far East. After the establishment of the Bolshevik Far Eastern Republic on April 6, 1920, Far Eastern areas with an ethnic Ukrainian majority attempted to secede and establish an entity called Green Ukraine.
24 June 1917 - First All-Ukrainian Far Eastern Congress at Nikolsk-Ussuriysky formed the Far Eastern Kray Rada (Land Council).
January 1918 - Second All-Ukrainian Far Eastern Congress at Khabarovsk proclaimed Green Ukraine as part of the Ukrainian State (in spite of the lack of geographical connection).
April 1918 - The Third All-Ukrainian Far Eastern Congress asked for the creation of an independent Ukrainian state on the Pacific Ocean.
Summer 1918 - The Far Eastern Ukrainian troops (more than 5,000) enlisted by General Boris Khreschatitsky.
11 April 1920 - Order of Hetman Grigory Semyonov on the right of Far Eastern Ukrainians for national self-determination and autonomy in the limits of a united Far Eastern state of Cossacks, Buryats, and Ukrainians.
1922 - Proclamation of independence Zeleny Klyn (Green Ukraine).
1923 - Adoption of the constitution.
19 June 1940 - Zeleny Klyn (Green Ukraine) declared war on Antara and its allies.
(Based on Wikipedia materials