Ruthenia

Ruthenia / Карпатська Русь

Transcarpathian Ukraine / Subcarpathian Rus

Wiki[link] or Wiki[link]

Presently, it is the Transcarpathian Oblast' of Ukraine with the administrative center located in the city of Uzhhorod.
Before it was a part of Hungary and Czechoslovakia.
It gained an autonomous status within Czechoslovakia in 1938 and declared independence on March 15, 1939 only to be overrun next day by the Hungarian
troops. After WWII, it was annexed by the Soviet Union and in 1991 it found itself in the newly independent Ukrainian state.

The Rusyn nation movement is much stronger among diaspora than in the actual territory, but, in 2007 the Zakarpattia regional council petitioned the Ukrainian
government to recognize the Rusyns as a separate national minority the considerable controversy has arisen regarding the Rusyn separatist movement led by the Orthodox
priest Dmytro Sydor, which threaten to proclaim unilaterally the independence or try to join the Russian Federation...

Because there is a large Ruthenian diaspora, particularly numerous in the US, Canada but also in Vojvodina, Slovakia, Poland and elsewhere, its voices influence the Ruthenian politics.
The Zakarpattla Oblast in the Ukraine has an
area: 12.777 sq km
pop : 1.245.000

Note that there is another version of this flag which you can find in this [link] and this [link]