But a government crackdown and waning public interest mean the second anniversary of the Bolotnaya Square protest is going largely unnoticed.
Moscow authorities have banned any public event on or near the square, in stark contrast with their decision last year to allow hundreds of people to rally in commemoration of the protest.
Police have also detained dozens of people who came to support the defendants outside a Moscow court where verdicts were being heard in February and March.
Amnesty International has accused Russian authorities of "doing all they can to scupper any protests to mark the second anniversary" of the ill-fated protest, during which hundreds of peaceful protesters were detained and scores injured.
PHOTO GALLERY: A Look Back At The Bolotnaya Protests
A total of 28 people have been charged in the case, which has drawn international condemnation as part of a ruthless Kremlin campaign to crush dissent.
Nine of them have been handed prison terms ranging from 2 1/2 to 4 1/2 years on charges of taking part in "mass unrest" and assaulting police.
Protester Mikhail Kosenko was sentenced to forced psychiatric treatment.
Another defendant, Aleksandra Dukhanina, received a suspended three-year sentence.
A further 11 defendants were pardoned in December under a national amnesty.
Six are still awaiting a verdict.
All but two of the defendants have denied wrongdoing.
Rights activists say Russian authorities are deliberately drawing out the trials to sap public interest in the case.
The deepening crisis in Ukraine and Russia's annexation of Crimea have further contributed to eclipse the plight of those jailed.
"There are obviously many more Russians who know about Ukraine than Russians who know about Bolotnaya," Anastasia Rybachenko, one of the amnestied defendants, told RFE/RL. "But it doesn't matter. What matters is how many more people can potentially still hear about it."
A student and activist with the "Solidarnost" opposition movement, Rybachenko fled to Europe after police raided her Moscow home in July 2012.
She has not returned to Russia since.
Rybachenko maintains that the Bolotnaya protest was overwhelmingly peaceful.
"Nothing unusual took place on Bolotnaya Square," she said. "This could have happened, and has happened, at numerous other rallies during which police caused confrontations."
She backs claims that police deliberately created bottlenecks at the rally to provoke skirmishes.
"Authorities wanted to falsify the narrative from the start and show that abuses and illegal acts were allegedly committed," she said. "But this is not true. Authorities simply sought to intimidate people."
The trial against defendants Aleksei Gaskarov, Aleksandr Margolin, Ilya Gushchin, and Yelena Kokhtareva is set to resume on May 14.
They, too, are charged with participating in mass riots and attacking police officers.
The remaining two defendants, opposition figure Sergei Udaltsov and Leonid Razvozzhayev, are accused of instigating the violence on Bolotnaya Square as part of a campaign to stir an antigovernment revolt across Russia.