Short answers, pulled from the story.
The Treaty of Pereiaslav transformed Ukraine into a protectorate of the Tsardom of Russia in 1654. This political shift triggered a massive movement of people from Ukrainian lands to Russian territories shortly after the treaty was signed.
The 2010 census identified that there were 1,927,988 people who were 1.40% of the total population in Russia. This figure represents a significant drop from previous decades and marks them as the eighth-largest ethnic group within the country.
Green Ukraine or Zeleny Klyn is part of Far Eastern Siberia located on the Amur River and the Pacific Ocean. The territory consists of over one hundred thousand square kilometers and had a population of 3.1 million in 1958.
Starting from 2014 a number of Ukrainian activists and organisations were prosecuted in Russia based on political grounds. A ban of Ukrainian organisations in Russia followed including the Ukrainian World Congress and the closure of a Ukrainian library in Moscow.
The settlement of people beyond the Ural mountains began in the 1860s for the Ukrainian settlement known as Grey Ukraine or Siry Klyn. Altogether 1,604,873 emigrants from Ukraine settled the area before 1914.