For years, it was shrouded in secrecy, then infamy, and after 48 hours of confusion and claims of a "rebellion" in Russia, questions about the notorious Wagner Group and the intentions of its leader Yevgeny Prigozhin were still swirling Monday.

The group has been a key piece of Russia's strategy in Ukraine, with Wagner forces being used to hold cities like Bakhmut. Prigozhin had sharply criticized Russian military leaders for weeks, calling the top brass incompetent, even traitorous.  

Tension between Russia's defense ministry and Wagner escalated dramatically Friday when Prigozhin alleged that Russian forces had attacked Wagner camps in eastern Ukraine, killing dozens of his men. Late Friday, Prigozhin issued video taped remarks that appeared to call for a rebellion against Russian military leadership, but he was characteristically vague in defining his plans.

Prigozhin's Wagner forces left Ukraine and marched into Russia Saturday, seizing control of the Russian military headquarters for the southern region in Rostov-on-Don, which oversees the fighting in Ukraine. 

• Wagner boss, "Putin's butcher," says Russia at risk of facing "revolution"

Russian President Vladimir Putin called the uprising "a stab in the back" in a televised address Saturday morning.

"All those who prepared the rebellion will suffer inevitable punishment," Putin said. "The armed forces and other government agencies have received the necessary orders."

What is the Wagner Group? 

Wagner is actually a group of entities that operate as a private military company, or PMC. These PMCs can be hired by governments for security or combat services. 

They aren't uncommon: The United States has used private military companies during the wars in Iraq and Afghanistan. However, there are differences between the commonly accepted definition of a PMC and Russia's version of the companies. 

"In NATO countries, in Western countries, the main logic behind using private contractors when it comes to security and defense policy has been the flexibility of resources," said Dr. András Rácz, a Russian expert at the German Council on Foreign Relations. "However, on the Russian side, the logic has been different. Russia, from the beginning, perceived these companies as a way of exerting state power in a covert way."

Who is Yevgeny Prigozhin? 

As Wagner's publicity has grown, so has that of its shadowy founder, Prigozhin. His work running a catering company with Kremlin contracts earned him the nickname "Putin's chef," but Prigozhin long denied any connection to the group before finally admitting to being its founder last year.

"Prigozhin is a mastermind of media and also is the mastermind of social media," said Kateryna Stepanenko, a Russia analyst at the Institute for the Study of War, a public policy research based in Washington, D.C. "While Putin and his propagandists have been dominating the Russian television and traditional outlets, Prigozhin is innovative because he had weaponized a network of military correspondents, military correspondents and bloggers." 

Prigozhin is wanted by the FBI for "Conspiracy to Defraud the United States." The federal law enforcement agency is offering a $250,000 award for information leading to Prigozhin's arrest for allegedly overseeing the political and electoral interference of the St. Petersburg, Florida-based Internet Research Agency from 2014 to 2018. The agency, for which Prigozhin was the primary funder, worked to interfere with the 2016 U.S. presidential election, the FBI alleged.

Prigozhin openly and increasingly criticized Russia's top military commanders as the country failed to make significant gains in Ukraine. Meanwhile, he has positioned himself as a hero.

"He knows that his key differentiator from the Kremlin propaganda is that level of criticism, level of honesty, you know, that things are not really going as well, and criticism sells," Stepanenko said. "And I think that that's the platform that he's really trying to advance on and solidify himself as a prominent figure in Russia."

Now, after seemingly squaring off against Putin in the brief weekend "rebellion" and being banished to Belarus, what's next for Prigozhin?

"People keep saying that he's marked for assassination," Jeff Hawn, a Russia expert at the London School of Economics, told CBS News on Monday, as the Kremlin tried to show it was business as usual after the chaotic weekend.

"There's a very good chance," said Hawn, adding that if there was an attempt on Prigozhin's life, "I don't think it might come from the Kremlin. I think it might come from the Ministry of Defense, because he embarrassed them hugely. But then again, he's been marked for assassination since the nineties."

Where else has Wagner worked and how does it make money? 

Wagner first popped up in Ukraine in 2014, when soldiers in unmarked uniforms appeared to help pro-Russian forces illegally annex territory for Russia. Before that the group is believed to have been involved in supporting Russian forces in Syria. 

In 2022, the private army became a major part of Russia's invasion, even recruiting fighters from Russian prisons and promising them pardons to beef up numbers on the battlefield, though Prigozhin said in February that the practice would be stopped.    

In addition to deploying Wagner troops to Ukraine, the Wagner Group has been active in Africa, where some nations have turned to the private army to fill security gaps or prop up dictatorial regimes. 

"In most cases, they provide training for local military forces, local security forces, but they are also engaged in VIP protection, also in guarding. And if necessary, they are able to conduct also high intensity operations, I mean real combat," said Rácz.

• Wagner Group accused of using rape and murder to control African mining town

In some countries, like the Central African Republic, Wagner exchanges services for almost unfettered access to natural resources. A CBS News investigation found that Russian cargo flights stopped in the country twice a week, possibly smuggling billions of dollars' worth of gold back to Russia. 

In addition to gold, CBS News also found Wagner was involved in illegal timber harvesting in CAR, another lucrative source of income.  

Putin said on June 27, just after the failed Wagner uprising, that the Russian government had paid more than $1 billion to the Wagner Group during over the last year.

"The state paid to the Wagner group 86.262 billion rubles (around $1 billion) for salaries for fighters and incentive rewards between May 2022 and May 2023 alone," the Russian president said in a televised meeting with law enforcement officials.

Wagner Group charged with war crimes 

As the operations of the once-shadowy group have become more public, so have their tactics. 

Wagner mercenaries have been accused of atrocities, including mass murder and rape, across Africa and alongside Russian forces in Ukraine. 

In Ukraine, fighters have been charged with thousands of war crimes. When previously asked for comment, the Wagner Group dismissed questions from CBS News as boorish and provocative, and insisted the company did not commit these crimes. 

In addition to their actions on the battlefield, military experts say Wagner recruits have been poorly equipped or even used as cannon fodder. U.S. officials estimate that about 30,000 Wagner fighters have been killed or wounded so far in Ukraine, all while Russia's advance has stalled or been pushed back, raising questions about the future of the group, and its leader, Prigozhin. 

Experts said it's possible the group could be replaced by Putin. 

"I think that Wagner, insofar as it's been useful in Ukraine, could certainly be replaced by others. Where you start to have much more of an issue in replacing Wagner and in replacing Prigozhin is in a place like sub-Saharan Africa," said Catrina Doxsee, an associate director and associate fellow for the Transnational Threats Project at the Center for Strategic and International Studies. 

"As the U.S. and other Western countries, including in Europe, try to dislodge Russia's influence and try to make the argument against Wagner, there really needs to be this conversation about viable alternatives," for countries in the developing world to meet their security and development needs.

Where does the Wagner Group's name come from?

The group's name appears to come from a man credited with co-founding it, Dmitry Utkin, a former officer in Russia's military intelligence agency, the GRU. Utkin retired from the Russian security services but went on to serve as a senior military command for the Wagner Group, a role he's believed to still hold. 

A nationalist with Nazi sympathies, Utkin's callsign in the Russian services was said to have been "Wagner" — a nod to Nazi leader Adolf Hitler's love for the 19th century German composer of the same name. 

Reporting contributed by Andy Triay and Cara Tabachnick.

In:
• Wagner Group
• War
• yevgeny prigozhin
• Ukraine
• Civil War
• Russia
• Vladimir Putin

Haley Ott

Haley Ott is an international reporter for CBS News based in London.

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