The death of Russia’s most prominent opposition leader, Alexei Navalny, at a remote Arctic prison on Friday ended one of the most audacious political careers of modern times and left wartime Russia without its most charismatic anti-war voice.

Navalny, whose death was reported by Russian authorities, stood as the most outspoken critic of President Vladimir Putin for more than a decade, harnessing broad opposition to the Russian leader more successfully than any other foe of the Kremlin. After surviving a poisoning widely seen as the Kremlin’s doing in 2020 and recovering in Germany, Navalny returned to Russia in 2021 and was immediately arrested.

But Navalny, a joking, gregarious, straight-talking former real estate lawyer, stayed relevant even from prison, publishing Instagram posts via messages relayed by his lawyers that were at once humorous and outraged. He pleaded with Russians not to give up or give in to their fears, and railed against the “criminal” war in Ukraine, which he said would bring the “continued impoverishment of Russian people.”

The reports of his death stunned his supporters and politicians around the world. Mikhail Vinogradov, a Moscow political analyst, described it as the most shocking death of a Russian politician in the country’s post-Soviet history. Russians gathered for impromptu vigils in cities around the world, while images of people laying flowers at memorial sites in Russian cities ricocheted across social media.

“I wanted to believe that Russia had its own Nelson Mandela,” a 28-year-old man said in an interview from the southern city of Rostov-on-Don, asking his name not be used for his safety. “Today, this man is gone.”

Putin was notified of Navalny’s death, his spokesperson said, but did not comment on it. President Joe Biden, at the White House, said it was clear that “Putin is responsible for Navalny’s death.” And in Munich, in an unscheduled appearance at the podium of a high-level security conference, Navalny’s wife, Yulia Navalnaya, pledged that Putin’s government would be “brought to justice.”

Navalny’s aides, who have been forced into exile and are headquartered in Lithuania, said they could not immediately confirm their boss’s death. On Saturday, they said, his lawyer and relatives were expected to arrive in the remote Arctic town where he was being held. But by Friday evening, they acknowledged that they believed the worst.

There was no clarity about the precise circumstances of Navalny’s death, other than a terse statement from Russia’s federal prison service declaring that he lost consciousness after going for a walk and that medical workers were unable to resuscitate him.

But Western leaders like Biden, as well as Navalny’s supporters, said it was clear that the ultimate responsibility for his death lay with Putin — who, three years ago, made the decision to imprison his most threatening political nemesis.

Since then, Navalny was subjected to increasingly harsh treatment in prison, as well as new charges that extended his sentence into the next decade — a sign that Putin was determined not to allow Navalny to reemerge as a powerful voice of dissent.

In prior years, Navalny had established a nationwide political network, using his populist rhetoric and YouTube exposes about corrupt officials to attract supporters well beyond Moscow’s liberal middle class.

The Kremlin sought to tamp down the day’s emotions. Putin appeared at a routine event in the Ural Mountains region, where he was asked about topics like robotics, government subsidies and engineering schools and did not mention Navalny. Dmitry Peskov, his spokesperson, later said it was “absolutely unacceptable” for foreign officials to blame the Kremlin because “there is no information about the cause of death.”

The announcement of Navalny’s death came just a month before Russia’s presidential elections, when the Kremlin will look to portray Russians as united behind Putin and his bid for a fifth term. Analysts expect the Kremlin to try to couple his surefire electoral victory with fresh gains on the front in Ukraine, where Russian forces have been taking the initiative against a Ukrainian army struggling amid dwindling Western support.

As the third year of the war nears, Putin’s control of domestic politics appears nearly total, with his most prominent surviving opponents either in jail or in exile. Street protests are immediately snuffed out, and thousands of Russians have been prosecuted for criticizing the war.

Offering high salaries to military recruits, the Kremlin has managed to wage its invasion without resorting to a second military draft, meaning that most Russians have been able to go on with their daily lives. The West’s far-reaching sanctions have not crippled Russia’s economy.

But to some analysts, Navalny’s death is a reminder that Putin’s power may be more tenuous than meets the eye. Navalny was adept at harnessing Putin’s liabilities, like corruption and simmering discontent with the war — which are likely to remain flashpoints after Navalny’s death.

“Navalny tended to sense the vulnerable points, rather than creating them,” Vinogradov said.

With Navalny gone as a leader channeling public anger, some opposition figures believe that new focal points for dissent could emerge.

Mikhail Khodorkovsky, a leading Russian opposition organizer and former oil tycoon who spent 10 years in Russian prison, said that Putin’s foes now needed to unite and to harness Navalny’s legacy. Navalny’s death, he said, showed that rather than consolidate around a single leader, Putin opponents needed to form a coalition to battle the Kremlin.

“A coalition as a system is far more stable,” he said. “If one person goes, others will remain and new people will appear.”

In Russia, a key question is whether the Kremlin follows Navalny’s death with a new round of repression and censorship. Even in death, political analyst Tatiana Stanovaya said Friday, Navalny poses a problem for the Kremlin.

“A lot will depend on whether the regime overreacts, which may become an issue in and of itself,” Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center, wrote. “They will have to deal with Navalny’s legacy.”

The power of that legacy was already on display within hours of Navalny’s reported death. Russians placed mounds of flowers and candles at the snowy Solovetsky Stone memorial in Moscow, which is dedicated to victims of repression under Josef Stalin.

In front of the Russian Embassy in Berlin, a former Kremlin consultant turned opposition figure, Marat Guelman, said he believed that Navalny’s death had the potential to reenergize Russia’s beleaguered and disparate opposition groups.

“I hope,” he said, “that in Russia, one hero will be replaced by 100 heroes.”

The New York Times News Service