The widow of Aleksei A. Navalny said on Monday that she would carry on her husband’s work to challenge President Vladimir V. Putin’s autocratic rule, presenting herself for the first time as a political force and calling on his followers to rally alongside her.
Mr. Navalny’s sudden death in prison, which was announced by the Russian authorities on Friday, left a vacuum in a decimated Russian opposition. His supporters had wondered whether his wife, Yulia Navalnaya — who long shunned the spotlight — might step in, despite immense challenges, to fill the void.
In a video released on Monday, Ms. Navalnaya, 47, signaled that she would. She said she was appearing on her husband’s YouTube channel for the first time to tell his followers that the best way to honor his legacy was “to fight more desperately and furiously than before.”
“I am going to continue the work of Aleksei Navalny and continue to fight for our country,” Ms. Navalnaya said. “I call on you to stand beside me, to share not only in the grief and endless pain that has enveloped us and won’t let go. I ask you to share my rage — to share my rage, anger and hatred of those who have dared to kill our future.”
The nearly nine-minute video, which showed Ms. Navalnaya seated with her hands folded on a marble surface under dramatic lighting, was crafted as an introduction of sorts to a new leader of the fractured pro-democracy movement against Mr. Putin. Long plagued by infighting and competing egos, the movement has withered under a multiyear crackdown in Russia that has left its most prominent leaders exiled, jailed or dead.
Ms. Navalnaya had often pushed back against suggestions that she enter politics, telling Germany’s Der Spiegel magazine last year that “I don’t think this is an idea I want to play with.”
On Monday, however, she presented a different face in trying to rally her husband’s followers, suggesting that there was no alternative and saying that the movement should derive strength from his memory.
“I know it feels impossible to do any more, but we have to — to come together in one strong fist and strike with it at this maddened regime, at Putin, at his friends and his bandits in uniform, at these thieves and killers who have crippled our country,” she said.
The dangers and hurdles Ms. Navalnaya faces in trying to assume her husband’s mantle and unite the opposition to Mr. Putin from outside Russia are significant.
The Russian government in 2021 disbanded Mr. Navalny’s Anti-Corruption Foundation inside the country by declaring it an extremist organization, sending the group’s main investigators fleeing into exile, where they continue to work and try to reach Russian audiences.
Cooperating with the organization from inside Russia has been made tantamount to abetting terrorism, limiting its ability to recruit the type of young grass-roots members who had electrified past efforts. Supporters of the Kremlin have tried to use the group’s exile to cast it as irrelevant or a puppet of Western security services.
Ms. Navalnaya cannot return to Russia without the threat of arrest. In June 2023, amid rumors that she might attend one of her husband’s many trials, the state-owned network RT quoted an unidentified law enforcement source as saying that Ms. Navalnaya could be arrested on charges of supporting an extremist organization if she were to return.
And much of Mr. Navalny’s appeal to his followers was personal, thanks to his unyielding humor, muckraking zeal and infectious certainty about the capacity for individual Russians to change the country in the face of cynicism and repression.
Ms. Navalnaya, seething with anger, suggested on Monday that she had no choice but to try. The immediate cause of Mr. Navalny’s death remains a mystery, but his family and team have accused Mr. Putin of killing him through a brutal incarceration.
“In killing Aleksei, Putin killed half of me, half of my heart and half of my soul,” Ms. Navalnaya said on Monday. “But I have another half left and it is telling me I have no right to give up.”
She echoed remarks from President Biden last week blaming Mr. Putin for her husband’s death and suggested Mr. Navalny’s team was investigating the circumstances of the death.
“We will name names and show faces,” she said.
She also directly addressed a question that many of Mr. Navalny’s followers have been asking after his death: Why did he return to Russia after his poisoning in 2020, knowing that he would almost certainly be killed?
In theory, she said, Mr. Navalny could have taken up a new life in exile and stopped speaking out against Russian corruption and fighting.
“But he couldn’t,” she said. “Aleksei more than anything else on earth loved Russia, loved our country and you all. He believed in us, in our power, in our future and that we deserved better. He didn’t believe it just in words but in deeds — so deeply and sincerely that he was ready to give his life for it.”
Ms. Navalnaya said that she wanted their two children to live in a free Russia — the “only way for his unthinkable sacrifice not to be in vain.”
Her rousing message was largely welcomed by Mr. Navalny’s supporters, many of whom have been driven out of the country and feel immobilized by grief.
It came as the Russian authorities continued to refuse to hand over Mr. Navalny’s body to his mother in a remote Arctic town close to the prison where he died.
Mr. Navalny’s spokeswoman, Kira Yarmysh, said on Monday that the authorities had told his mother that the body would be subjected to a “chemical examination” for another 14 days.
“One of the lawyers was literally pushed out” from the morgue in the Arctic where Mr. Navalny’s body is believed to be, Ms. Yarmysh said in a post on the social media platform X. She added in another post, “They lie, buy time for themselves and do not even hide it.”
Russian investigators initiated an inquiry into the causes of Mr. Navalny’s death shortly after it was reported, a procedural move that allows them to hold the body for longer than normal.
Ivan Zhdanov, the head of Mr. Navalny’s Anti-Corruption Foundation, said that the delay meant that Russian officials were “cleaning up traces of their crime.”
“They are waiting for the wave of hatred and rage toward them to calm down,” Mr. Zhdanov said in a post on Telegram, the messaging app.
The Kremlin spokesman, Dmitri S. Peskov, rejected any suggestion of impropriety on Monday, saying that the investigation into Mr. Navalny’s death has been continuing “in accordance with the Russian law.”
More than 63,000 people have signed a petition to Russian investigators demanding the release of Mr. Navalny’s body, a campaign initiated by a Russia-based human rights group, OVD-Info.
Mourners have brought flowers to makeshift memorials across Russia, paying tribute to Mr. Navalny with an act of grief that has also served as a form of protest in a country where even the mildest dissent can risk detention.
The Russian authorities have tried to tamp down the scale of public mourning. Flowers have been quickly removed from memorials and the police have detained hundreds of people.
Russian news outlets have also sought to play down Mr. Navalny’s death, limiting mention of it on television broadcasts. Russian officials have accused the West of jumping to conclusions in blaming Mr. Putin, describing the allegations as yet another example of Western unfairness toward Russia.
Anton Troianovski and Neil MacFarquhar contributed reporting.