Rus'
The history of the Ukraine-Russia relationship dates back at least to the tenth century. Kyiv (Rus. Kiev) was the site of the Christianization of the Eastern Slavs when Grand Prince Volodymyr Sviatoslavych accepted Christianity on behalf of the people of Rus’. Kyiv was at that time the principality that ruled over Rus’ — a polity covering the territory of much of present-day Ukraine, parts of present-day Belarus, and parts of present-day Western Russia. Kyiv is seen as the mother of all Eastern Slavic cities and the birthplace of Eastern-Slavic statehood and Christian Orthodoxy. Over the period of Mongol domination of Rus' (thirteenth century), the western part and the eastern part diverged culturally, linguistically, and politically.

Fourteenth through Nineteenth Centuries
By the time the Mongol domination of the region was over, the western part of Rus’, including Kyiv, had become joined to Western powers, and in the ensuing centuries it would both continue to develop its distinct (Ukrainian) language and culture, and also become part of the Lithuanian state, and later the Polish state. In the east there was a struggle for dominance among new ascendant principalities, among them Moscow, which ultimately prevailed over what had been the eastern part of Rus’. Muscovy, later Russia, became a massive imperial power over the next several centuries, and different parts of Ukraine were incorporated under the Russian state beginning in the late seventeenth century. Over the eighteenth and nineteenth centuries Ukrainians asserted their distinct ethic and cultural identity and distinct national language, and several bids were made for an independent Ukrainian state, but ultimately none were successful.

Twentieth Century
When the Russian Empire broke apart following the Bolshevik Revolution in 1917, this was seen as a window of opportunity for Ukrainian independence, but after five years of military conflicts between the Bolsheviks and competing Ukrainian factions representing competing visions of Ukrainian statehood, Ukraine became one of the nominally independent Soviet republics that were in fact centrally ruled from Moscow. In the ramp-up to WWII Moscow did terrible violence to Ukrainian agrarian society by imposing a brutal rapid collectivization plan and forcibly requisitioning almost all agricultural production for consumption in Russian cities and for international trade to support the USSR’s breakneck industrialization program. The result was the 1932-33 Holodomor famine in Ukraine that killed around four million people. During WWII Ukrainians suffered massive civilian and military casualties (totaling around eight million) and accounted for a large part of the Soviet resistance to the Nazi invasion. Nonetheless, certain facts conspired to create a trope of the Ukrainian WWII-era traitor and even Nazi collaborator in the Russian collective consciousness after the war. One was an active Ukrainian movement to try to break away from USSR and form an independent state once the contest with Germany had exhausted itself. Another was the fact that many Ukrainian displaced persons left in Western Europe after the war sought emigration rather than repatriation and told people in the West about the horrific repressions in the Stalinist Soviet Union. In general, for the rest of the post-war Soviet era, Ukraine was effectively treated by Moscow as a peripheral territory of Russia, as it had been under many of the Tsars.

Post-Soviet Reality
With the dissolution of the Soviet Union in 1991 Ukraine became a modern sovereign state. In 2005 Putin called the collapse of the Soviet Union the “greatest geopolitical catastrophe of the twentieth century.” Since then he has pursued a project to reassert Russian influence over the territories of the former Soviet Union. Putin’s Russia has addressed anxieties about Ukraine drifting away from Moscow’s influence and towards the West by trying to maintain Kremlin-friendly regimes in Ukraine. Ukrainians have staged rebellions against these regimes, culminating in the Euromaidan protests in 2014 and the ousting of Kremlin loyalist Viktor Yanukovych. Throughout this period the Kremlin’s messaging has repeatedly reactivated WWII-era notions of proponents of an independent Ukrainian nation as traitors or even Nazi collaborators, and referred to those who assert Ukrainian independence from Russia as nationalists, extremists, fascists, and neo-Nazis. This is the origin of the claim that the current Russian armed forces’ “special operation” in Ukraine is aimed at “denazification” of the country.