Aleksei A. Navalny built Russia’s largest opposition force in his image, embodying a freer, fairer Russia for millions. His exiled team now faces the daunting task of steering his political movement without him.

The movement has found a leader in Mr. Navalny’s widow, Yulia Navalnaya, who has presented herself as the new face of the opposition to President Vladimir V. Putin. Ms. Navalnaya, 47, is aided by a close-knit team of her husband’s lieutenants, who took over running Mr. Navalny’s political network after his imprisonment in 2021.

Maintaining political momentum will be a challenge. Few dissident movements in modern history have managed to stay relevant, let alone take power, after the death of a leader who personified it. And so far, Mr. Navalny’s team has made little attempt to unite Russia’s fractured opposition groups and win new allies by adjusting its insular, tightly controlled ways.

A spokeswoman for Mr. Navalny’s team, Kira Yarmysh, did not respond to questions or interview requests; nor did several of Mr. Navalny’s aides.

In their public statements, Mr. Navalny’s top aides have said their movement will have to change to continue confronting Mr. Putin without its leader, though it is unclear what the new strategy might be.

Even from prison, Mr. Navalny had “managed to support us, to infect us with optimism, to come up with projects, come up with cool political ideas,” Leonid Volkov, Mr. Navalny’s chief political organizer, said in a video published on social media last month. “Without Aleksei, things will not be as before.”