The Kremlin says Alexei Navalny died Friday in an Arctic prison. After surviving a poisoning and still making the decision to return to Russia, President Vladimir Putin's most significant opposition figure was serving 19 years on extremism charges.

What do we know about how Navalny died?

Amid accusations that he was murdered, what motivations would Navalny's enemies have for acting against him now? 

Not long after a number of Western commentators predicted Putin's demise over the Ukraine war, what does Navalny's death mean for Putin's tightening grip on Russia?

CBC's Briar Stewart explains.