In September 2008, just days after Lehman Brothers collapsed, Abu Dhabi finalised its purchase of Manchester City Football Club in a deal that came “to define the use of sport as a platform for projecting soft power”, says the . The club, chaired by Khaldoon Al Mubarak, went on to win eight Premier League titles.

Yet it now faces “an existential crisis”, having been found guilty by an independent panel of artificially inflating its financial position by more than £900 million, in breach of financial fair play rules, via “sham” commercial deals that overstated its income. The club's proud Abu Dhabi royal owners find themselves in the dishonourable position of presiding over “one of the biggest scandals in Premier League history”.

The debacle, and City's initial “aggressive, confrontational stance” against the football authorities, is a “rare mis-step” for Khaldoon Al Mubarak – a smooth operator with a reputation for tightrope-walking his way through tricky politics, says . He appears to have broken the “cardinal law” of ambassadors: “don't embarrass the boss”.

Khaldoon Al Mubarak, 50, is one of Abu Dhabi's most powerful non-royals. He more usually “straddles global finance, diplomacy and football with a polished assurance that mirrors the emirate's meticulously managed image”, notes an profile. That has made him a leading power broker in the emirate's international relations. He is “diplomatically in charge of the UK file as well as the China file… and the main liaison with the US administration”.

As group CEO of Mubadala, he is also “the world's longest-serving head of a sovereign investment fund” – a key figure overseeing oil-rich Abu Dhabi's $1.5 trillion in wealth.

Who is Khaldoon Al Mubarak?

Khaldoon Al Mubarak learned the tough realities of politics the hard way, says . In 1984, when he was eight, his father Khalifa Al Mubarak – a diplomat serving as the UAE's ambassador to France – was gunned down in Paris by the Abu Nidal terrorist group, a forerunner to Hamas. Their justification was that the UAE had become too seduced by “American imperialism”. The young Khaldoon was “mentored” by the Abu Dhabi royal family in the wake of the killing. Indeed, he became a “quasi-adopted son”, says .

The royal family hired Al Mubarak when he graduated from Tufts University in Massachusetts. In 2002, he was selected to lead the newly founded Mubadala Development Company, which was “charged with helping diversify Abu Dhabi's oil-dependent economy and investing its hydrocarbon wealth in new industries and infrastructure”, says the .

He enjoyed such success – including negotiating an annual Formula One Grand Prix in 2007 – that he was the shoo-in to lead the revival of Manchester City. There are plenty of people with good things to say about him – including “suave” and “incredibly capable”. One Dubai business associate goes further. “He's a good human being… he's funny, he's probably the best friend you can get if you are lucky. And he's clean.” Certainly, Al Mubarak has avoided personal association with controversies that have dogged the emirate. Until now.

The saga is far from over. Manchester City has rejected the ruling and lodged an appeal. Meanwhile, the UK government is fretting over the possible fallout if sanctions imposed on the club prompt Abu Dhabi to turn off its massive investment spigots. Ultimately, the Emiratis may be forced to sell Manchester City.

Al Mubarak, who has UK diplomatic immunity, “could well emerge from this fiasco largely untarnished”, says , because City is such “a tiny part of his portfolio”. Still, these are uncomfortable times.

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