Today Russia is trying to make themselves the defenders of the "ethnic Russian-speakers" who have lived for ages within what we understand to be the geopolitical area dubbed the Ukraine. But when you begin playing with/depending on history, you are on a slippery slope.
Go back in time to well before the end of the first millennium C.E. and you will be looking at a large area centred on Kiev (old spelling; sorry) that was first ruled and then settled by a people known historically as the Kievan Rus. The situation rose out of what was first a trading relationship between the locals and those who we would end up calling Vikings. Even way back then the critically located Kiev was a major node on the trading map between east and west. This is but a crude sketch but if Putin wants to establish an historical hegemony over Ukraine, he would be acting more historically accurately if he handed the rule of western Russia and the Ukraine to Denmark.