Perhaps unsurprisingly for a man with the nickname ‘Mystic Mac’, it was Conor McGregor who first predicted that a super-fight with Floyd Mayweather would one day take place. That fight takes place tonight.

“If you’re asking would I like to fight Floyd Mayweather, I mean, who would not like to dance around the ring for $180m?” McGregor replied to a playful question from late-night host Conan O’Brien, in July 2015, on whether he would ever be tempted into switching sports. “I would certainly box him if the opportunity arose,” he smiled. “Most certainly.”

The question — and indeed, McGregor’s answer — seemed like throwaway comments, not intended to be taken seriously while the charismatic Irishman had his heart completely set on dethroning José Aldo as the UFC featherweight champion of the world. McGregor’s comments made headlines, and then quickly faded away.

Mayweather v McGregor: In numbers Show all 19 1 /19 Mayweather v McGregor: In numbers Mayweather v McGregor: In numbers Mayweather v McGregor: In numbers What are the numbers behind the eagerly-anticipated super-fight between the two men? Getty Mayweather v McGregor: In numbers Zero The number of defeats Mayweather has suffered in his 19-year professional career Getty Images Mayweather v McGregor: In numbers 1 The number of times Mayweather has touched the canvas throughout his professional career. He came back to win the fight via a unanimous decision Getty Images Mayweather v McGregor: In numbers 2 The number of UFC championship belts McGregor (briefly) held when he defeated Eddie Alvarez at UFC 205 Zuffa LLC via Getty Images Mayweather v McGregor: In numbers 3 The number of times McGregor has been defeated: losing to Artemji Sitenkov in 2008, Joseph Duffy in 2010 and Nate Diaz in 2016 Getty Images Mayweather v McGregor: In numbers 12 McGregor’s age when he began boxing at Crumlin Boxing Club under two-time Olympian Phil Sutcliffe Getty Images Mayweather v McGregor: In numbers 13 The number of seconds it took McGregor to knock out José Aldo at UFC 194, to win the UFC Featherweight Championship Getty Images Mayweather v McGregor: In numbers 23 The number of fights Mayweather has won by decision Getty Images Mayweather v McGregor: In numbers 25 In 2016, Mayweather was ranked by ESPN as the greatest boxer, pound for pound, of the last 25 years Getty Images Mayweather v McGregor: In numbers 40 Mayweather’s age. He is 12 years older than McGregor Getty Images Mayweather v McGregor: In numbers 46% Mayweather’s average connect rate, according to CompuBox and compiled over his past nine fights. It’s one of the best in the history of the sport Getty Images Mayweather v McGregor: In numbers 49 The number of wins Mayweather has racked up in his professional career. He requires only one more to surpass Rocky Marciono’s flawless record of 49-0. Getty Images Mayweather v McGregor: In numbers 84-8 £150,000 Mayweather’s sterling amateur record. He won the national Golden Glove championships at three different weight classes Getty Images Mayweather v McGregor: In numbers $150,000 The fine dished out to McGregor for throwing a bottle at Nate Diaz in a press conference ahead of UFC 202. The fine has delayed the announcement of a boxing match against Mayweather Getty Images Mayweather v McGregor: In numbers 1,650,000 The pay-per-view buy rate for McGregor’s eagerly anticipated rematch against Diaz at UFC 202, making the event the most successful non-boxing PPV event in the history of fightsports Getty Images Mayweather v McGregor: In numbers 19,500,000 The number of PPV buys Mayweather has garnered in his entire career Getty Images Mayweather v McGregor: In numbers $34,000,000 McGregor’s career earnings, as estimated by Forbes at the start of June 2017 Getty Images Mayweather v McGregor: In numbers $1,300,000,000 The total revenue Mayweather has generated in his career Getty Images Mayweather v McGregor: In numbers 14,000,000,000 The number of social media impressions Conor McGregor made in 2016 Getty Images for Wynn Las Vegas

It was Mayweather who rekindled the speculation, that December. In an interview with FightHype on the worldwide adulation McGregor had received for knocking out Aldo in just 13 seconds, the American complained that he would never receive such acclaim from the public because of the colour of his skin.

“They say he talk a lot of trash and people praise him for it, but when I did it, they say I’m cocky and arrogant,” Mayweather observed. “So biased! Like I said before, all I'm saying is this, I ain't racist at all, but I'm telling you racism still exists.”

This time, it didn’t take the other man the best part of half a year to respond. “Don’t ever bring my race into my success again,” McGregor commented in a long Instagram post, the very next day.

“I am an Irishman. My people have been oppressed our entire existence. And still very much are. I understand the feeling of prejudice. It is a feeling that is deep in my blood … If you want we can organise a fight no problem. I will give you a fair 80/20 split purse in my favour seen as your last fight bombed at every area of revenue.”

A feud was born.

The pair began to frequently exchange barbs on social media, with things coming to a boil in May 2016. British tabloid The Sun reported that the two men were “on the verge” of agreeing to a deal, with an unnamed source telling the paper that “Floyd is obsessed with making Conor eat his words”.

The story attracted so much attention that Dana White, the president of the UFC, felt compelled to finally address the situation. He laughed off suggestions the super-fight would ever take place, instead pointing out that McGregor was contracted to the UFC, and would thus be in breach of contract should he attempt to organise a fight himself away from the confines of the Octagon.

White’s dismissive comments appeared to spur Mayweather into action. First he insisted the fight was “possible”. Then he told a journalist that he was a retired man and would only countenance returning to professional sport in order to fight McGregor. And then he pressed the nuclear button, offering the Irishman just $50m to fight him in what people were already describing as a billion-dollar bout.

McGregor, a man who enjoys nothing more than dressing from head to toe in Gucci and Givenchy and parading his eclectic collection of super-cars on social media, was stung.

Super-fight preview: Floyd Mayweather v Conor McGregor

“He’s getting old now,” he thundered in an interview. “I have the size, I have the reach, I have the height, I have the youth. He needs me. I don’t need him.”

Later, while promoting his rematch with Nate Diaz — a fight which he would ultimately win and which broke all previous UFC pay-per-view records — McGregor added Mayweather was “running around the Showtime offices begging for those executives to come up with $100 million cash for me, to fight me.”

Mayweather's management initially cooled the excitement (Getty) (Getty Images)

Excitement grew when McGregor beat Diaz and obtained a Californian boxing license, all in the space of a few days. But in December 2016, Mayweather’s promotions head, Leonard Ellerbe, poured cold water on the prospective fight, insisting it was “a calculated effort to gain more fans”.

A full year after Mayweather had first responded to McGregor’s jibes, the billion-dollar fight looked to be dead in the water.

Step forward Dana White. Having himself rubbished the chances of the fight, just like Ellerbe, the UFC president changed tact. Perhaps aware of the staggering sums on offer, he made a public offer to Mayweather: $25m for each man plus a cut of the PPV. May weather flatly rejected the offer — but the talks were back on.

Things began to move quickly in March 2017. First Mayweather told fans on his ‘Undefeated’ tour that he was “coming out of retirement to face Conor McGregor”. White then told Conan O’Brien he was increasingly confident a deal was close, while the Nevada Athletic Commission paved the way for McGregor to obtain a boxing license with them.

And then in May, McGregor insisted in an interview that he had signed his half of the agreement.

The next month, on Wednesday 14 June, both men announced the fight on their individual social-media accounts.

“THE FIGHT IS ON,” McGregor posted on Twitter, along with a mocking picture of himself side-by-side with Floyd Mayweather Snr. “It’s official!" replied Mayweather on Instagram, along with a short promotional video confirming the involvement of Showtime.

Both men revealed that the date for the fight had been set for August 26. And so, one of the longest-running sagas in the history of combat sport reached a temporary conclusion.