Vladimir Putin's fierce rival and critic Alexei Navalny has died, according to the prison service. The Russian opposition leader, who was the most prominent and persistent domestic foe of President Vladimir Putin, had been serving a 19-year sentence on an extremism conviction. He had been incarcerated in central Russia’s Vladimir region, 140 miles east of Moscow. Navalny has been behind bars in Russia since January 2021, when he returned to Moscow after recuperating in Germany from nerve agent poisoning that he blamed on the Kremlin. Before his arrest, he campaigned against official corruption and organized major anti-Kremlin protests.