Polish actress Michalina Olszanska plays Mathilde Kschessinska in “Matilda.” (AP/AP)

A blockbuster film about the romance between Russia's last czar and a ballerina has inflamed a simmering culture war between artists and conservative activists, testing the Kremlin's ability to promote conservative values without unleashing a reactionary pogrom.

Last week, masked Russian ­police burst into an apartment complex and arrested three men, including the leader of an extremist religious group called Christian State-Holy Rus, for calling on supporters to burn down movie theaters planning to show the film "Matilda." Someone had already tried to set fire to the director's studios and to several cars near his attorney's offices.

"Burn for 'Matilda,' " a note near a burned-out automobile read. 

"Matilda," set for release next month, is the story of Nicholas II's three-year romance with the ballet dancer Mathilde Kschessin­ska. It occurred before his marriage to the German princess ­Alexandra and his coronation as czar. Nicholas and his immediate family, who were murdered by the Bolsheviks in Yekaterinburg in 1918, are saints, canonized by the Russian Orthodox Church in 2000.

The film has been criticized by mainstream voices in the church, including Bishop Tikhon, who is the powerful head of Moscow's Sretensky Monastery and rumored, though never confirmed, to be President Vladi­mir Putin's personal confessor. 

"From the point of view of history, it's just a desecration of history, a desecration of our culture," Tikhon said at a lecture in March.

A former film student who was baptized at age 24, Tikhon also said he had read the script for "Matilda" and called the trailer "drivel." But he hotly denied that the church wanted the film banned.

"Honestly, we already ban things too often in the name of the church," Tikhon told an ­audience at the Russian Military Historical Society, a body of ­politicians and other thinkers presided over by the head of
the Russian Foreign Intelligence Service. "One after another. And the church is being turned into some kind of committee of censors. Stop. It won't lead to anything good."

Since his reelection in 2012, Putin has championed conservative values in Russia, while religious conservatives have become more prominent in United Russia, the party founded by Putin. In an acid state-of-the-union speech in 2013 — the same year that Russia banned "gay propaganda" and jailed members of the band Pussy Riot for a protest song in a church — Putin lashed out at the "destruction" caused by "nontraditional values" from the West.

Controversial legislation supported by religious conservatives, including a bill this year that decriminalized some forms of ­domestic violence, have made their way onto Putin's desk and into law. 

Controversial art and theater productions have been targeted by conservative activists, and shows with controversial subject matter, such as a Bolshoi ballet about Rudolf Nureyev that explored his homosexuality, have been canceled.

Demonstrators carry an icon depicting the canonized family of Nicholas II during a protest against the movie “Matilda” at the Church of the Resurrection in Moscow. (MLADEN ANTONOV/AFP/Getty Images)

But the turn to violence by a group of far-right activists has produced a rare crackdown from the Russian government and a backlash against the conservative Russian parliament member most critical of the film, Natalia Poklonskaya, a former prosecutor from Crimea who had the film reviewed for blasphemy.

"It's like a mini-ISIS is starting," Stanislav Govorukhin, a film director and member of parliament who heads the Duma Cultural Committee, said at a hearing this month, referencing the Islamic State.

The opponents of "Matilda" are led by Alexander Kalinin, the founder of Christian State-Holy Rus, who claims to have found God during a near-death experience (and trip through hell) while on vacation near the Sea of Azov in 2010. He told the Meduza news agency this month that he founded Christian State-Holy Rus later in 2010 and that it had 350 members.

He also said he supports a theocracy along Iranian lines — Christian, of course, rather than Muslim.

After Kalinin was arrested, ­police said he was also under investigation for the attack near the lawyer's offices. Poklonskaya, trying to withdraw herself from the controversy, said that she had personally demanded his arrest. 

For director Alexei Uchitel, whose 2010 film "The Edge" was nominated for a foreign-language Academy Award, the backlash was more than he expected when he decided to make a movie based on the diaries of Kschessinska. That she and Nicholas, then a grand duke, had an affair is little doubted by historians. 

Uchitel said he had feared for the lives of those closest to him after receiving death threats and after attempts to burn down his studio. The arrests are a "good step" and may persuade several theater chains that dropped the film over safety concerns to reconsider, he said.

"Sure, I expected the film to provoke some discussion," Uchitel said in an interview. Noting the October release date, he added: "But they haven't even seen a single frame. They have no idea what's there."

Poklonskaya was a leading supporter of Crimea's annexation from Ukraine in 2014. Young, telegenic and patriotic, she was made a member of parliament in 2016. 

"Here you are, Natalia Poklon­skaya, the new sex symbol of Russia," a reporter for state ­television said to her during a segment just days after Putin signed Russia's annexation of Crimea. "Oh my God," she replied. "No, I want people to recognize me as a prosecutor."

In parliament, Poklonskaya has drifted away from her image as a law-and-order figure toward religious conservatism. In an interview with the news outlet Komsomolskaya Pravda, she complained that the actors portraying Nicholas (Lars Eidinger) and his psychiatrist are German.

"Really, [Eidinger is] an actor who spits on our history, who treats us and our traditions with a lack of respect and says Russia is a cultureless country, that a lack of morality and culture rule here because you just need to support gays and the opposition," she told a reporter in a 30-minute video interview in which she occasionally referred to herself in the third person. "And he's the person who's invited to play the main role of the film."

Referring to Nicholas as "our sacred ruler," she also accused Eidinger of taking part in the occult. 

Uchitel confronted Poklonskaya at the Kremlin at a holiday reception in June. The encounter wasn't filmed, but one picture was released last week, showing Poklonskaya in a black dress looking past the suited director.

Uchitel asked her to watch the film. "I'm not going to watch the film," she said, both have recalled. "I have the reports."