Yevgeny Prigozhin, the Russian mercenary leader now reportedly dead, was at the heart of a mutiny against Moscow's military leadership in June.
Mr Prigozhin, 62, rose to prominence as a Kremlin confidant and restaurant tycoon who was nicknamed “Putin's chef”. He was at the forefront of Russia's February 2022 invasion of Ukraine, where his fighters – including thousands of convicts he recruited from prison – led the Russian assault on the city of Bakhmut in the longest and bloodiest battle of the conflict.
He used social media to trumpet Wagner's successes and wage a feud with the military establishment, accusing senior officers of incompetence and treason.
In June, he led a mutiny in which Wagner fighters took control of an army base in the southern city of Rostov-on-Don and shot down a number of military helicopters, killing their pilots, as his force advanced towards Moscow.
President Vladimir Putin called it an act of treachery that would be paid with a harsh response.
The revolt was defused in a deal whereby the Kremlin said that in order to avert bloodshed, Mr Prigozhin and some of his fighters would leave for Belarus and a criminal case against him for armed mutiny would be dropped.
Confusion has surrounded the implementation of the deal.
The Kremlin said he attended a meeting with Mr Putin five days after the mutiny.
On July 5, state TV said an investigation against him was still being pursued, and broadcast footage showing cash, passports, weapons and other items it said were confiscated from one of his properties.
But in late July, Mr Prigozhin was photographed in St Petersburg while a Russia-Africa summit was taking place in the city.
This week, he appeared in a video which he suggested was shot in Africa, where Wagner has operations in several countries.
Prigozhin admits he is Wagner Group leader
It was not until the war in Ukraine that Mr Prigozhin admitted what had long been suspected in the West: that he was the leader of the private army known as the Wagner Group.
But in taking on board Mr Prigozhin's manpower, the Kremlin largely indulged his erratic and outspoken personality.
His tirades against the Russian army came to a head during the battle for Bakhmut, where Mr Prigozhin said his men had been left to “perish senselessly” without ammunition.
Crossing another line, Mr Prigozhin openly rejected Mr Putin's explanation for invading Ukraine in February 2022.
How Prigozhin became friends with Vladimir Putin
Mr Prigozhin and Mr Putin were both born in Leningrad in what was then the Soviet Union and have a long history.
Mr Putin used to take foreign leaders to the restaurants that Mr Prigozhin owned after turning his line as hot dog seller into a catering business.
He provided meals to the Kremlin and to Russian public schools. In 2010, Mr Putin opened a factory for the catering business that was financed with state loans.
What is the Wagner Group? – video
“Vladimir Putin saw how I built a business out of a kiosk, he saw that I don’t mind serving to the esteemed guests because they were my guests,” Mr Prigozhin recalled in an interview published in 2011.
Mr Prigozhin, who is believed to have served prison time for theft and fraud in his youth, later came under scrutiny in the US as investigators looked into claims that Russia had meddled in American elections.
Mr Prigozhin has acknowledged that he founded and financed the Internet Research Agency, a company Washington claims is a “troll farm” which interfered in the 2016 US presidential election.
In November 2022, he said he had meddled in US elections and would do so again.
Last year, he made the admission: “We have interfered, we are interfering and we will continue to interfere.”
The US sanctioned Mr Prigozhin, targeting three private aircraft and a yacht, for his links to the group.