The three hours of both parts shown with no break at the Museum of Modern Art, Ivan the Terrible/Ivan Groznyy and The Boyars’ Plot/Ivan Groznyy: Skaz vtoroy--Boyarskiy zagovor, is at once wonderful and terrible, a milestone of cinema history, an unfinished swan song for the master auteur, and an example of art shaped (and lessened) by political exigencies and propaganda.

Returned in disgrace from the United States and Mexico in the mid-‘30s, writer-director Sergei Eisenstein rehabilitated himself sufficiently with cheerleading epic Alexander Nevsky -- likened by more than one to run-of-the-mill DeMille or Curtiz -- to be awarded the Order of Lenin and named artistic chief of Mosfilm and allowed to start extensive research for a projected three-part saga of Ivan IV, duke of Moscow and the first anointed czar of Russia.

Filmed over twenty months at central Asian Alma Ata studios (far from hostilities) for 1945 release, Part I was welcomed as a glorification of the heroic sixteenth-century unification of Russia and of the heroic twentieth-century struggle for its survival against fascist Germany. Begun a year after the victory, the second part ran into trouble when Stalin loathed it, certainly too close for comfort paralleling Ivan’s and his descents into monomaniacal dictatorship, cruelty and secret police, and it was banned by the Party Central Committee until 1958. (Part III, The Battles of Ivan, was never to be realized.) Indeed, certain flashbacks here in II and an awkward final third featuring a semi-masque switched from b&w into garish Agfa-process red tints, raise questions as to how much of it can be wholly attributed to Eisenstein and his inseparable DP Edouard Tissé, for the director had died of a heart attack in 1948, at fifty.

Nevsky had signaled a bit of a departure from his D.W. Griffith-influenced five types of montage, the juxtaposition of short scenes for emotional over intellectual effect. In Ivan he would return to the earlier technique, with the addition of sound, including scoring by Prokofiev, and with beautiful Expressionistic sets, stark light and shadows, and severely angled shots that further sharpened contrast. (One disappointment in the colored sequences is precisely the loss of definition and of this chiaroscuro.)

Conflict is set in motion from the first, as amidst Orthodox magnificence and chants the Metropolitan crowns Ivan Vasilovich. Before this first “Czar of all the Russians” turns his clean-shaven manly visage to the camera, the faces of supporters and opponents are dwelt on, angled in exaggerated ruffs, cloaks and cowls.

Needing to be distinguishable among the bewildering cast are wife-czarina-to-be Anastasia Romanovna (Lyudmila Tselikovskaya), a calming influence on her idealistic stern husband; favorite Prince Andrei Kurbsky (Mikhail Nazvanov), who lusts for his ruler’s wife and, remembering a battlefield affront, later defects to Poland; co-favorite Fyodor Kolychev (Andrei Abrikosov), who retires to monastic life only to return as monk Philip, elevated to Metropolitan and a leader of his fellow landowning-nobility boyars against Ivan’s consolidation of power in himself through personal guards, the oprichniki; and the czar’s aunt, Efrosinia Staritskaya (Serafima Birman), a scheming witch in black with a wicked walking stick who covets the throne for her simpleton son Vladimir Andreyevich (Pavel Kadochnikov). Many carry over into Part II, along with a few non-courtiers employed by Ivan, but all revolve around him.

The czar is a commanding Nikolai Cherkasov, who had played Nevsky in 1938 and was an Order of Lenin deputy of the Supreme Soviet. His Ivan wins over the rebellious peasants, marches to and defeats insolent Asian Kazan and thus initiates Moscovy-Russia’s expansion eastwards, battles Livonia, Sweden and Poland for control of the Baltic, and initiates White sea trade with “our cousin” England. Spanning both parts, these successes harden boyar determination to regain lost control. Ivan’s near-fatal illness during which they refuse to recognize his infant son Dmitri as heir apparent, and Efrosinia’s melodramatically staged poisoning of Anastasia, isolate and turn the czar inward.

His original light-colored finery is traded for severe ascetic black, his hair lengthens, while his figure, face and even pointed chin beard grow El Greco angular and gaunt. Forced by plots to abandon the capital, he is memorably imaged atop his retreat castle, called back by columns of commoners who wind into a bare white landscape.

Ivan’s revenge for treason, an eye for an eye, a loved one for a loved one, is cruel but probably no worse than the reality, and may have been the way to unite the disparate Motherland and keep it united. Few are familiar with Lord Acton’s sentence immediately following his observation on power’s corrupting: “Great men are almost always bad men.” Rage, repentance and prayer, it is said, dominated the historical Ivan the Terrible. Eisenstein’s Ivan is a magnificence of parts, four-fifths of it a visual wonder beyond the man himself.

(Released by Artkino Pictures; not rated by MPAA.)