Galina Vishnevskaya, the soaringly talented Russian soprano who spent years in exile in Washington with her husband, the cellist-conductor Mstislav Rostropovich, after they stood up for art in defiance of the Soviets, died Dec. 11 in Moscow. She was 86.

Her death was announced by the Opera Center in Moscow, which she had founded. No cause of death was released.

Over a long career spent on both sides of the Iron Curtain, Ms. Vishnevskaya fulfilled a variety of responsibilities, to art, to her family and to history. She and her husband were regarded as symbols of the struggle for personal and cultural freedom and against Soviet repression.

Each famed in their native country, they were exiled after they took in Nobel Prize-winning author Alexander I. Solzhenitsyn at a time when he was in deep disfavor with the Soviets.

During their time in the United States — and particularly in Washington, where her husband was a towering presence as musical director of the National Symphony Orchestra for 17 years — she sometimes was identified as Mrs. Mstislav Rostropovich.

Russian soprano Galina Vishnevskaya with her husband, the Russian cellist-conductor Mstislav Rostropovich, at the piano in February 1959. They married in 1955 after a few days of courtship. (Erich Auerbach/Getty Images)

But in Russia, before exile in 1974, Ms. Vishnevskaya had achieved fame even beyond that of her celebrated cellist husband. At the height of her vocal power in the 1950s and ’60s, Ms. Vishnevskaya was, The Washington Post once wrote with little exaggeration, the musical Empress of all the Russias.

Amid the deprivations experienced in Leningrad in World War II, a time in which she nearly starved, Ms. Vishnevskaya began her career singing in operettas.

In 1952, she won a national competition to train with the Bolshoi Opera Company, the leading opera company in the Soviet Union.

By the next season, she was the company’s reigning soprano. One of her first parts, Tatiana in Tchaikovsky’s “Eugene Onegin,” would remain a signature role for her.

Some of the most eminent composers of the 20th century wrote for her. British composer Benjamin Britten wrote the soprano part of his masterpiece “War Requiem” for her. Dmitri Shostakovich dedicated to her his “Seven Romances.”

On infrequent trips permitted by the Soviets, Ms. Vishnevskaya sang in the most prestigious opera houses in the world, including London’s Royal Opera House in Covent Garden, Milan’s La Scala and New York’s Metropolitan Opera. She appeared at the Met for the first time in 1961 in the title role of Verdi’s “Aida.”

(Her appearances at the Met, critic Raymond Ericson once wrote in the New York Times, were like comets — “sudden, infrequent, capable of lighting up the sky.”)

Her repertoire spanned the Italian, French and English canon, but she was most associated with Russian composers such as Tchaikovsky, Prokofiev, Rimsky-Korsakov and Shostakovich. Beyond its exquisite tone, and deep vibrato, admirers said, her voice possessed an unmistakably Russian intensity.

Ms. Vishnevskaya held the rank of “people’s artist of the Soviet Union” and was one of the most renowned musicians in the country, at one point batting away the advances of then-Prime Minister Nikolai A. Bulganin.

Ms. Vishnevskaya ran afoul of the Communist authorities in the 1960s, when she and her husband sheltered Solzhenitsyn in their dacha.

At the peak of their careers, the musicians were suddenly blacklisted. Concerts were canceled. Such performances as were permitted could not be advertised. The couple feared that they might face houses of empty seats. Once revered, their names were purged from reference books.

In 1974, aided by U.S. leaders such as Sen. Edward M. Kennedy (D-Mass.), Ms. Vishnevskaya and her husband received the exit visas needed to come to the United States.

Denounced in the Soviet Union as “ideological degenerates,” they lost their Soviet citizenship in 1978. It was restored in 1990 by Mikhail Gorbachev.

Ms. Vishnevskaya and her husband lived in Washington for years. He won fame and adulation, but life in exile was more painful for her.

An inanimate instrument may endure for centuries, but the human voice at its peak lasts only a fraction of a lifetime. Already in her late 40s when she left Russia, Ms. Vishnevskaya struggled to relaunch her career.

She largely retired from opera in 1982, after a farewell performance of “Eugene Onegin” in Paris. But she continued as a presence on the world music stage. A production of Rimsky-Korsakov’s “The Tsar’s Bride,” directed by Ms. Vishnevskaya, was performed in Washington in 1986.

And she continued to appear with her husband, who died in 2007 at 80. They were praised for their virtuosity and the high emotion they conveyed. Former Washington Post music critic Joseph McLellan once wrote that their “intuitive collaboration” came “as close to lovemaking as anything that happens in classical music.”

Galina Pavlovna Ivanova was born Oct. 25, 1926, in St. Petersburg, then known as Leningrad. She said her mother, a gypsy, gave her up at 6 weeks. Her father was an alcoholic and a Communist Party functionary.

Ms. Vishnevskaya was raised largely by her paternal grandmother. She grew up on an island naval base and gave some of her earliest performances to Russian soldiers wounded during World War II. She married a soldier, Georgi Vishnevsky, and was reported to have divorced him because he did not want her to sing.

Her early adulthood was marked by tragedy. She married Mark Rubin, a violinist, and gave birth to a child who died in infancy. She once told an interviewer that she had dug her baby’s grave.

Ms. Vishnevskaya almost lost her own life to tuberculosis. Doctors told her that she would not survive if she did not submit to a procedure in which her lung would be collapsed. Knowing that the loss of a lung would end her career, she leapt from the operating table as the needle was readied.

She and Rostropovich married in 1955 after a few days of courtship. “My God, such a beauty!” Rostropovich thought when he saw her, he told Time magazine.

Ms. Vishnevskaya’s artistic output transcended music. Her autobiography, “Galina: A Russian Story,” came out in 1984 to great praise.

In her 80s, Ms. Vishnevskaya played the title character in a Russian movie about a woman visiting her grandson at the front in a war zone. The performance was highly lauded.

Survivors include her two daughters, Olga and Elena, both musicians.

Reflecting on her life and on those who had sought to besmirch her reputation, she told The Post that Soviet history was “remade over and over, like a pair of pants being retailored to a different height and build.”

She said one should not be affected by how Soviet leaders created and destroyed their idols.“Their removing you from your pedestal is as meaningless as their raising themselves to their own pedestal.”