Sunderland owner Kyril Louis-Dreyfus has already accomplished a lot at a young age.

The 25-year-old is the heir to a multibillion pound fortune, married to a former Australian model and is the youngest chairman in English football.

Louis-Dreyfus (right) became Sunderland chairman at the age of 23

But Louis-Dreyfus arguably faces the biggest challenge of his life in restoring fallen giants Sunderland to their once proud glory.

The Frenchman became the youngest chairman in English football at the age of 23 when he completed his takeover of the Black Cats last year.

He purchased the League One club from Stewart Donald, who kept a minority shareholding along with Juan Sartori and Charlie Methven.

Louis-Dreyfus has been interested in football since going to Marseille games with his late father Robert, who owned the French club until his death in 2009.

His mother Margarita is also a billionaire and still remains a minority shareholder at Marseille despite selling her majority in 2016.

KLD was even said to have considered his a career on the pitch as a player before he was sidelined by injury.

Louis-Dreyfus grew up a keen supporter of Marseille with his late father as the owner

However, Louis-Dreyfus, whose brother Maurice was a DJ before joining him on the board at Sunderland, was ready to give up on football before finding the Wearside outfit.

"Following the sale of OM, I stuck to one idea: we don't do anything in football anymore, it's a rotten business," he told French outlet L'Equipe.

"But Sunderland is a special project, really.

"The fervour of the people is reminiscent of that of Marseille. There were more spectators on average than in half of the Premier League clubs.

"You can't buy this! In cities like Zurich, Monaco, nobody is interested in football, it limits the possibilities of expansion."

He vowed not to get involved in football again after his family sold their majority in Marseille

KLD hasn't enjoyed the type of instant success he'd have wanted with Sunderland currently in their third successive season in League One.

And it could end up being a fourth should the Swiss-born billionaire fail to appoint the right manager to succeed axed Lee Johnson.

He is clearly not afraid to make big decisions and and his biggest yet could be the appointment of Roy Keane as manager.

The Manchester United legend is one of football's toughest characters and has not been a manager in 11 years - but that hasn't put off the young Sunderland owner.

The Black Cats currently sit third in the league, two points behind Wigan Athletic, but the Latics have three games in hand so whoever takes over has a big job on their hands.

KLD has already attempted to give the club a much needed boost following their 6-0 loss to Bolton with the emotional return of Jermain Defoe.

Louis-Dreyfus gave Sunderland fans a much needed boost by sealing Defoe's return

The Sunderland chairman was just three-years-old when Defoe scored his first ever Premier League goal for West Ham against Ipswich in 2001.

He'll be desperate for the 39-year-old striker to hit the ground running to give him more time to make the right appointment in the dugout.

And no one has more faith that he'll do so than Vincent Labrune, who was president of Marseille and is now president of the French football league.

Labrune told L'Equipe: He has absolute passion. He takes up the torch [from his father]; there is ambition, pride.

"He has a good memory, he will feed on past mistakes. He will not flare up: it is not in his nature, and his mother, anyway, would not let him."