Ukraine was a large part of the front in the Great War, until Russia signed a peace treaty with Germany and crushed the Bolshevik revolution.
In 1922 Nikolai Leonid led an uprising against Russia for independence, thought it was shortly and brutally crushed. Several more peacefull attempts at independence were made, but all ended in failure.
Despite earlier revolutions, Ukraine was becomming a prosporus region by 1935. Though, anti-Russian sentiment had been growing. By 1938 anti-Russian sentiment lead to violent harassment by the Ukrainians. Long resenting them for their imperialist occupation.
In 1940 all out rebellion broke out in all of the major cities along with bloody guerilla warfare. Eventually they would lose, but some still fought on throughtout the years, never giving in. The Ukrainians never stopped until they had independence. Even though it would be unlikely they would win, they did score some victories through the years. And then eventually after being sick of the crap the populace had to put up with in 1953 yet another uprising broke out after yet another failed attempt at peaceful independence. This conflict was brutal and bloody, but in the end, the Russians won their final victory in 1956 as they finally eliminated the resistance. It would be a long time to rebuild the damages and repair everything, but they got it done by 1965.
Eventually in 1970 two Finnish people murdered the Tsar as he was giving a speech, and Russia dissolved into many squabbling states, but fairly quickly Ukraine managed to define it's borders and they managed to sustain themselves. Then Boris Leonid came to power, a former general and descendant of Nikolai Leonid, he lead the nation into a war against the Muscovites after a series of borders engagements initiated by the Muscovites, eventually succeeding in capturing all of their lands.
Six years later, a Hungarian plot set Ukraine against its European allies, eventually resulting in the Hungarian Invasion of Ukraine. The attack was beaten back quickly, but not without significant aid of Poland. This only frustrated the already disgruntled people, leading to a series of public strikes and eventually a referendum pertaining joining Poland as a federate territory. The poll resulted in favor of joining, ending the period of autonomous Ukraine.