Finally, after years of build-up, perhaps English football's biggest and most controversial contest is set to begin.

On one side, the Premier League. On the other, its defending champions and dominant force Manchester City.

City face 115 charges for allegedly breaking the financial rules of the competition they have won for a record-breaking four consecutive seasons.

Those charges will be heard at an independent hearing, which is set to start on Monday at an unknown location, subject to any late legal delays. Billed as sport's 'trial of the century', it is expected to run for 10 weeks, with a verdict expected in early 2025.

It marks a defining stage in a legal dispute the like of which the game has never seen and which could bring seismic consequences for both sides.

This, after all, involves one of the world's most successful clubs being accused of serial cheating by the very league it has dominated for years. A club at the centre of a global network of 13 teams across five continents, owned by a billionaire member of Abu Dhabi's ruling family, whose sovereign wealth has transformed the landscape of the sport.

The case involves an unprecedented catalogue of 115 allegations spread over 14 seasons, including multiple charges of subverting the regulations by failing to provide accurate financial information.

City have always strongly denied the charges, and while the speculation is intensifying, no-one knows what the outcome - expected early next year - will be.

If found guilty of the most serious charges, City would risk being forever associated with one of the biggest financial scandals in sport. City could, in theory, face a points deduction serious enough to condemn them to relegation - or even expulsion - from the Premier League.

Such a fate would cast a long shadow over City's achievements, plunge the future of the manager and squad into uncertainty, and possibly spark claims for compensation from other clubs. It has been suggested that such a stain on the reputation of City and the club's owners could even affect Britain's relationship with the United Arab Emirates (UAE), a key Gulf ally and trading partner - whose president is the brother of the club’s majority owner Sheikh Mansour.

Equally, if City are cleared following a legal battle that is already thought to have cost both sides tens of millions of pounds, the viability of rules intended to safeguard the league's sustainability and competitiveness will be in grave doubt.

But whatever verdict is reached after a hearing set to last several weeks, the impact could be profound, dictating the story of this season.

It is difficult to overstate the seriousness and scale of a saga threatening to exacerbate widening divisions in the game, and which has become a test case for the Premier League’s authority and credibility at a time when it already faces an array of challenges.

Last month, at a London launch event celebrating the start of the new season, but dominated by questions over financial regulations, the Premier League's chief executive Richard Masters told BBC Sport that "it is time now" for the City case to be resolved.

Choosing his words carefully, but perhaps hinting at the toll the case has already taken and the turmoil it has unleashed, he added: "It's been going on for a number of years and I think it's self-evident that the case needs to be heard and answered."

So 10 years after City were first punished by Uefa for breaching its financial rules, six years after the Premier League opened an investigation into the club, and 20 months since they were charged, how did we finally get here? What exactly does the club stand accused of? What forces are at play? And what is at stake?

In June this year, a Portuguese computer hacker in witness protection called Rui Pinto was reported to have told a conference that he was in possession of "millions of documents" that could be relevant to the City case.

Pinto was well known to the game's authorities. The 34-year-old was the man behind the Football Leaks website which has exposed confidential football transfer and contract information.

Despite always claiming he was a whistleblower, last year he was handed a four-year suspended sentence by a court in Lisbon after it found him guilty on counts of attempted extortion, illegal access to data, and breach of correspondence. But his threat to release more information - confirmed by his lawyer - was a timely reminder of the continuing role of one of the key figures in this remarkable story.

Back in 2018, the German publication Der Spiegel claimed City had manipulated contracts to get round Uefa rules, and said that its source was a whistleblower they called 'John' - the pseudonym Pinto created Football Leaks under.

Der Spiegel had published leaked documents, including emails purportedly sent between top City executives (some of whom remain at the City Football Group), across several seasons following the club's Abu Dhabi takeover in 2008.

They alleged that these showed the club had inflated sponsorship revenue from state-owned airline Etihad and state-controlled telecoms firm Etisalat by disguising direct investment from its holding company (Mansour’s Abu Dhabi United Group, or ADUG) as sponsorship income by channelling the funds through the companies' accounts.

This, it was alleged, was a means of meeting 'financial fair play' (FFP) rules introduced by Uefa in 2011, and Profit and Sustainability Rules (PSR) brought in by the Premier League in 2012, limiting clubs' permitted losses.

There then followed further allegations of misreporting financial information centred on documents that claimed to show secret 'off-the-books' payments to then-manager Roberto Mancini via consultancy fees from a club in Abu Dhabi, and giving players more money than was officially going through the accounts so that recorded spending was less than it actually was.

City - who have always maintained that ADUG is a private fund rather than an arm of the state - refused to comment on any of Der Spiegel’s revelations, saying the leaked emails were obtained illegally, and that they were an “attempt to damage the club’s reputation”.

City - along with the companies involved - strongly denied breaking any financial rules. But that did not stop both Uefa and the Premier League launching investigations as a result.

City had already been fined millions of pounds by Uefa back in 2014 as part of a settlement after they were found to have breached FFP rules that were meant to make the game more sustainable, but which critics argue protect the historically biggest clubs by restricting investment by rivals, especially those with Middle Eastern backers.

Then, in early 2020, the club was hit with a two-year ban from European club competition after being found to have committed "serious breaches" of the governing body's regulations. An independent panel of Uefa's Club Financial Control Body concluded that City had been "overstating its sponsorship revenue in its accounts… submitted to Uefa between 2012 and 2016", adding that the club "failed to cooperate in the investigation".

Criticising what it called a "prejudicial" decision following a "flawed and consistently leaked process", City referred to a "comprehensive body of irrefutable evidence in support of its position", and appealed.

A few months later they were successful, the Court of Arbitration for Sport (Cas) overturning the ban, saying that it had found "no conclusive evidence that they disguised funding from their owner as sponsorship", and that most of the alleged breaches of rules were either not established or 'time-barred' because they fell outside the five-year statutory limit for prosecution.

Cas revealed that Sheikh Mansour had written a letter to the court insisting that he had “not authorised ADUG to make any payments to Etihad, Etisalat or any of their affiliates in relation to their sponsorship of MCFC".

However, it also found that City had committed a "severe breach" by failing to co-operate with Uefa’s investigation, with an initial £25m fine reduced to £8m.

For more than two years, the saga seemed to go quiet, but behind the scenes, the Premier League's investigation had continued. In July 2021 there was a dramatic glimpse of it, when a High Court judge revealed that the Premier League had effectively accused City of delay tactics by failing to agree to hand over documents, ordering the club to do so.

And then, in early 2023, came the most sensational twist in this saga to date, when, with City on their way to the third of four consecutive titles, and their first Champions League triumph, they were hit with that catalogue of charges, relating to every one of the years since the club was bought by Sheikh Mansour.