There are also “Ukrainians” who have been in Kiev for many generations, who are Kievan Rus... ie they speak and have always spoken russian, and ukrainian was at best a second language. They are also Orthodox and not Catholic, that still does not mean they were ever pro russian.
Before the communists came, both my grandfather and grandmother came from families that spoke russian and french at home. During World War II, my grandparents and father managed to escape westward, the rest of the family stayed behind. Some eventually moved to Riga, but since the fall of communism they are no longer welcome there.
What is the difference between written Russian and Ukrainian languages ?
Poles were expelled from Western Ukraine after the war, and the Soviets sent Ukrainians in to take their place.