The German Empire conquered Ukraine during World War I and was planning on either annexing it or installing a puppet king, but was defeated by the Entente, with major involvement by the Ukrainian <answer>Bolsheviks</answer>. After conquering the rest of Ukraine from the Whites, Ukraine joined the USSR and was enlarged (gaining Crimea and then Eastern Galicia), whence a process of Ukrainization was begun, with encouragement from Moscow.
What Ukrainian political group was involved in the defeat of the German Empire?
Bolsheviks