The Kremlin was never able to fully silence Navalny.

While the Kremlin authorities worked tirelessly over many years to silence Aleksei A. Navalny, they never entirely succeeded, not even by locking him up in one of the harshest penal colonies located above the Arctic Circle.

Using both his reputation as the most respected, most viable leader of the often beleaguered opposition movement — and his training as a lawyer with a wily understanding of loopholes in the system — Mr. Navalny always found ways to be heard.

From prison, he denounced the war in Ukraine and continued to spotlight the vast wealth accumulated by senior government officials. In his latest effort, he endorsed the idea that, during the presidential election from March 15 to 17, all Russians opposed to the war should protest silently by showing up at polling stations across Russia exactly at noon.

“While in prison, Aleksei Navalny remained the moral and de facto leader of the opposition to Putin,” said Fyodor Krasheninnikov, a Russian political commentator based in Brussels. “This certainly bothered the authorities.”

While in prison, Mr. Navalny used several methods to communicate with the outside world. Barred from seeing his immediate family members, he spoke to his lawyers and some of what he said invariably ended up on X, formerly Twitter, and other social media apps.

For example, starting in early 2023 he had a 15-point posting pinned to the top of his profile in X attacking President Vladimir V. Putin for the war in Ukraine and predicting defeat. Russia criminalized such comments early in the war, but Mr. Navalny, already sentenced to at least two decades in prison, had nothing to lose.