Mr. Pushkin created provocative displays of opposition to Lukashenko, a former Soviet bureaucrat who has held power in Belarus since 1994 through withering crackdowns on dissent and rigged elections, according to Western officials and rights groups.

In 1996, Mr. Pushkin painted a church mural in his hometown Bobr depicting the prophecy of the Last Judgment with the face of a hell-bound sinner reminiscent of Lukashenko. That part of the mural was ordered removed from public view.

Three years later, Mr. Pushkin hauled a red-painted hand cart full of horse manure to the presidential office in Belarus’s capital, Minsk, and dumped the load at the gates. He left a wooden plaque thanking Lukashenko “for the fruitful work” and drove a pitchfork through a Lukashenko poster. Mr. Pushkin received a two-year suspended sentence.

Mr. Pushkin’s death elevated him to martyr status among Belarus’s embattled opposition but is unlikely to rally any renewed push against Lukashenko after years of systematic repression. The jailing of government critics “constitutes an unacceptable practice that violates human rights,” said the Belarusian rights group Viasna.

Mr. Pushkin joined waves of anti-Lukashenko protests linked to elections in 2020. Lukashenko’s regime jailed the main opposition figures but faced a new slate of rivals led by women, including the wife of an activist who was put behind bars. Many top Lukashenko critics fled the country amid widespread arrests and allegations of torture.

Mr. Pushkin refused self-exile — even rejecting an offer of asylum from Ukrainian President Volodymyr Zelensky’s government in 2021 when Mr. Pushkin took part in an art exhibition in Kyiv. (He recreated his “Dung for the President” piece for the show.)

“There are two kinds of Belarusian artists,” he said to the news site Open Democracy in a 2011 interview. “Official and unofficial. But it’s not a question of ‘this art is good, this art is bad,’ it’s a question of complicity and conformism.”

In late March 2021, Mr. Pushkin was part of a team helping restore Bulgakov Palace, a 19th-century estate inspired by Versailles, when police raided his home. Journalists called Mr. Pushkin for comment as he was gilding one of the halls. “I have gold on my hands,” he told Radio Free Europe/Radio Liberty’s Belarus Service. Hours later, police came to the palace and dragged him off the scaffolding, according to media accounts.

The charges stemmed from a painting he made in 2012 depicting an anti-Soviet resistance fighter, Yevgeny Zhikhar, holding a machine gun. Prosecutors alleged the work, which was on exhibit at the time, was aimed at the “rehabilitation of Nazism.” (Lukashenko’s ally, Russian President Vladimir Putin, used similar rhetoric against Zelensky before Russia’s 2022 invasion of Ukraine.)

At Mr. Pushkin’s trial in 2022, he demanded he represent himself. Then, as the prosecution laid out its case, he rolled over on the bench in the defendant’s cage with his back to the courtroom. His supporters said that Mr. Pushkin’s painting celebrated the resistance fighter’s postwar stand against the Kremlin’s control rather than his earlier collaborations with Nazi forces.

When the guilty verdict was read, Mr. Pushkin revealed self-inflicted slash marks on his stomach in the shape of a cross. He was sentenced to five years in the Grodno penal colony.

Rights groups designated Mr. Pushkin as a political prisoner — among nearly 1,500 critics of Lukashenko’s government jailed in recent years, including 2022 Nobel Peace Prize winner Ales Bialiatski.

“Dictators fear artists [who] hold a mirror to the world, one that tyrants dread to look into,” said opposition leader Svetlana Tikhanovskaya, who ran against Lukashenko in the 2020 election and is the wife of a jailed anti-government blogger, Sergei Tikhanovsky. She later fled the country.

From prison, Mr. Pushkin made drawings of inmate life, including self-portraits with hollow cheeks and a burning gaze, and allegorical images often done in monochrome washes of red or blue. In one sketch, a group of bedraggled men look up at a butterfly that gives off rays as if from a religious icon — a type of artistry that Mr. Pushkin studied.

In another drawing, a figure appears standing stiffly, blindfolded and gagged.

Alexander Mikhailovich Pushkin was born on Aug. 6, 1965, in Bobr, about 80 miles northeast of Minsk, when Belarus was part of the Soviet Union. He graduated in 1983 from a fine-arts boarding school and enrolled at the Belarusian State Theater and Art Institute.

In 1984, he was drafted into the Soviet military and spent two years in Afghanistan, which Moscow’s forces occupied from 1979 to 1989. The ruthlessness of war, he said, changed his perceptions of life in the Soviet Union.

“That’s when I stopped being scared of the government, the KGB, the police,” he once said. “And it was only 20 years later that I came to realize I paint icons for Orthodox and Catholic churches by way of repentance for my cruelty — even if it was in a faraway land.”

He received his arts degree in 1990, a year before the collapse of the Soviet Union. His capstone project in art school, a huge mural, earned him a job as a state-funded artist in Vitebsk, near the hometown of painter Marc Chagall.

But Mr. Pushkin was already under increasing scrutiny. He was arrested during Belarus nationalist rallies in 1988 and 1989, including helping create posters that mocked Soviet-style ideology. In March 1991, Mr. Pushkin rode through Vitebsk on a donkey and then released doves to represent freedom.

After independence, Mr. Pushkin opened one of the country’s first private art galleries in 1993 and helped with stage design projects for performances such as “King Lear.” (Mr. Pushkin said in the documentary “A New Sky Over a New Land” that he came to the opening night with a monkey, which he left in the cloakroom.)

To boost his income, Mr. Pushkin developed expertise in restoring frescoes and icons, many of which were partially destroyed or hidden during the Soviet decades.

Survivors include his wife of 26 years.

During some court appearances over the decades, Mr. Pushkin said he tried to turn the proceedings into performance art with judges and others as unwitting foils. “Playing the holy fool is the highest form of freedom that’s ever existed at any time in our country,” he said in 2011.

He sometimes refused to walk into court and forced police to carry him to the docket. In one trial in 2019, he demanded the judge speak the Belarusian language, which is linguistically distinct from Russian. The judge complied.

“The police and the judge …. become part of the performance without realizing it themselves,” he said. “Though they do, naturally, realize what an absurd situation they’ve put themselves in.”