Yevgeny Prigozhin, leader of powerful Russian mercenary group Wagner, died in a plane crash on Wednesday, alongside the group’s alleged founder Dmitry Utkin.

“The Wagner leadership has confirmed the deaths of Prigozhin and Utkin,” according to the Wagner Group Telegram channel, which for several hours prior had urged the public to “not panic” as rumors swirled that Prigozhin had been aboard a small plane that crashed between St. Petersburg and Moscow.

Earlier in the day, Russian state-controlled media had reported that Prigozhin had been on the passenger list of a private jet that crashed in Russia’s Tver region. Later Wednesday, Russia’s Federal Air Transport Agency announced it had created a special commission to investigate the crash. “According to preliminary data, there were seven passengers and three crew members aboard the aircraft.” The statement added that investigators had already begun collecting evidence at the scene. They then released a list of names of those onboard, which included Prigozhin and Utkin. Russia’s Investigative Committee has launched a criminal case involving violations of air traffic and safety rules, under Article 263 of the Russian Criminal Code, according to local media.

The Wagner Group is a mercenary organization that operated in the shadows to advance Russian interests abroad — most notably in several African nations, Syria, and Ukraine.

Prigozhin started out as a hotdog vendor and convicted burglar before amassing fortunes with lucrative catering contracts following the ascent to power of longtime friend and Russian President Vladimir Putin.  He became a household name in Russia after taking on the role of political chief of Wagner.

After winning a key battle for the Ukrainian city of Bakhmut, Prigozhin grew increasingly belligerent over what he saw as the Russian Defense Ministry’s refusal to provide needed ammunition and other resources for his forces. After naming and shaming Russia’s top brass, Moscow ordered Wagner forces to sign contracts with the Defense Ministry — a move that would bring these private military contractors under the federal fold. Prigozhin refused to comply with the order, and shortly thereafter, led his troops into Russia, where they passed through multiple regions with little to no resistance. Within the space of several hours they reached the outskirts of Moscow.

Utkin, whose military call sign had been Wagner, was believed to have been the group’s founder. Though broadly known among Russian military watchers, Utkin shied away from the spotlight. He reportedly played an instrumental role in Wagner operations, with sources claiming he had personally been leading a convoy that had reached a location some 120 miles out of Moscow.

As the Wagner forces advanced, Putin accused Prigozhin of treason and vowed swift, tough action as the latter’s mercenary forces advanced through Rostov-on-Don and Lipetsk.

Later the same day, Prigozhin’s march halted abruptly and reversed course. At the time, Prigozhin announced:

In the course of a day, we marched to 200 km from Moscow. In that time, we did not lose a single drop of blood from among our fighters. Now the moment has arrived when blood could be spilled. Because of that, understanding that it would be Russian blood being spilled. Therefore, recognizing the grave responsibility that Russian blood would be shed on one side or the other, we are turning our columns back and moving in the opposite direction, back to the field camps, in accordance with plans.

After the about-face, Kremlin officials announced Russia would not pursue criminal charges against Prigozhin. “Criminal proceedings [against Prigozhin] will be dropped, and he will be leaving on his own accord for Belarus. If you’re asking about the nature of the guarantee that Prigozhin will be able to leave Russia — it is the word of the president,” Presidential spokesman Dmitry Peskov said Saturday in quotes carried by Russian state-controlled news outlet RIA Novosti.

Prigozhin continued to walk free, to the shock of many familiar with Putin’s prolific record of crushing his foes. The deaths of Prigozhin and Utkin occurred almost two months from the day of their short-lived uprising.