In the past 12 months, Conor McGregor has retired for a third time and has been caught up in repeated controversy.
He has 31 million followers on Instagram - and flogs his own clothing and whiskey brands. But recently Conor McGregor has seldom steered clear of controversy. Kim Bielenberg sets out his story so far.
On July 14, 1988, Conor McGregor arrived on this earth - and the colourful accounts of the event suggest that this was the birth of a legend who could not be ignored.
His father Tony described the scene in the maternity ward at the National Maternity Hospital: "His fists were clenched coming out of the womb, so he was ready to fight."
Even the midwife is reported to have chipped in with a prophetic remark: "This fella is going to be a boxer."
And you would not be surprised if a hospital orderly might have declared from the sidelines to the sound of singing angels: "Truly this man is the son of Muhammad Ali."
McGregor rose to become the highest-earning Irish sportsman on the planet in the relatively novel sport of Mixed Martial Arts.
He may have retired for a second time earlier this year, but he remains the most famous exponent of the Ultimate Fighting Championship (UFC).
Depending on your point of view, either it is a magnificent spectacle that mixes elements of boxing with the skills of wrestling - or else it is just a glorified scrap.
Last year, Forbes reported that McGregor was the fourth highest paid sportsperson in the world with annual earnings of €90m.
It was his fight with Floyd Mayweather - the clash of a veteran boxer with a UFC champion - that enabled McGregor to reach the peak of his fame and fortune. For that fight alone, he is reported to have pocketed €80m.
Right through his career, McGregor has evoked mixed responses - ranging from the adulation of fans wrapped in Tricolours, to the contempt of those who do not regard UFC as a respectable sport.
Some time ago, the Sunday Independent columnist Paul Kimmage questioned whether the mainstream media should engage with a sport he regards as "barbaric", and once admitted he was repulsed by it.
When McGregor fought Mayweather, the fight was widely regarded as a money-grabbing stunt of limited sporting significance.
It was compared to the occasion when Muhammad Ali fought a sumo wrestler, or the Battle of the Sexes between tennis players Billie Jean King and Bobby Riggs
The man from The New York Times showed scant respect for either party in McGregor's most famous bout: "Some wanted Mayweather to win, some wanted McGregor to overcome impossible odds - and some hoped that the two would manage to knock each other out."
McGregor has revelled in his nickname "Notorious", but since he fought Mayweather it is his notoriety outside the octagon of Mixed Martial Arts that has attracted attention rather than his actual endeavours in the ring.
His fans may admire the legend of him being born with a clenched fist, but detractors might hope that his fist would remain unclenched outside the ring.
In the last few days, video footage has emerged from an incident in the Marble Arch Pub in Drimnagh, where McGregor appears to throw a punch at an older customer at the bar counter.
In the footage, which was filmed in April, McGregor is standing at the bar ostentatiously pouring out shots of his own whiskey brand, Proper Twelve, to a group of people. He the appears to lash out with his left hand and strike a man who is sitting on a bar stool nearby. McGregor himself has yet to comment on the incident.
Since the video of McGregor's alleged whiskey shot was publicised, the fighter has suffered a backlash.
Staff at an Irish pub in Florida filmed themselves proudly pouring his brand whiskey down the toilet in a video that went viral.
Will the reputation of Ireland's most high-profile sportsman in the United States go down the toilet with the whiskey?
The charismatic president of UFC Dana White, the man who effectively turned McGregor into a superstar, brushed the incident aside this week - and said that he would still allow the Dubliner to fight.
He then made a rather disobliging remark about our way of life: "Listen, the Irish have been punching each other in the face in pubs for years."
The alleged punch is just the latest in a string of incidents that has found McGregor at the centre of controversy.
Last year, he plead guilty to disorderly conduct at a UFC event in New York. Several people were hurt when he hurled a trolley at a bus after a press conference in Brooklyn.
McGregor avoided going to jail after striking a deal which saw him do community service. He also had to take anger management courses and pledged to keep the peace for a year.
As his community service, McGregor reportedly assisted with "manual labour" at two New York churches. His lawyer Bruce Maffeo told the New York Post that he was put to work.
"By all accounts, it was a full day's work," the lawyer was quoted as saying. "He wasn't just sitting there throwing pencils at the ceiling."
Nobody can doubt that McGregor's rise to riches from his humble beginnings in Crumlin has been spectacular. When he first dedicated himself fully to Mixed Martial Arts, he was famously scraping by on very little as an unemployed apprentice plumber.
His father, Tony, fretted about him giving up what could be a well-paid trade in order to pursue his love of MMA.
But once Conor hit the big time, the fighter was able to buy a yacht for his father. It was called The 188 - a reference to the weekly dole money Conor had to live on. He is said to have chosen the name as it was a reminder of a life he never wanted to return to.
Some of the descriptions of McGregor's upbringing in the British and American media miss the target by painting a picture of a gangland dystopia.
The Sunday Times provoked some hilarity when it reported that McGregor had grown up in "the Gaelic speaking, council estate badlands of Tallaght, south of Dublin".
Although he was educated in Irish-speaking schools, he grew up in Crumlin and Lucan, where he moved as teenager to a humdrum suburban estate, which was hardly part of a gangland scene.
A profile of the fighter in the American magazine ESPN described his home city as a "clannish, parochial place" where "crossing the wrong street has traditionally been reason enough for an ass-whipping".
Growing up, McGregor was small in stature, but excellent at sport - particularly football. Like many boys from Crumlin, he gravitated towards the boxing club and soon found he had a talent. It was when he moved to Lucan that he became fascinated with Mixed Martial Arts through his friendship with another fighter, Tom 'the Tank' Egan.
By 2012, McGregor was starting to make waves in the Cage Warriors, a European equivalent of the UFC, and after six consecutive knock-outs, claimed the featherweight and then lightweight belts.
He then moved into the more high-profile Ultimate Fighting Championship, where again he became a champion and a household name.
In 2015, he won the UFC Featherweight Championship stunning José Aldo with a spectacular punch after only 13 seconds of the first round - it was the fastest victory in UFC title fight history. He then defeated Eddie Alvarez to take the lightweight crown.
Amid all the hoopla surrounding McGregor, mostly of his own making, his sporting talent is perhaps forgotten.
In 2015, he was tested for his athletic prowess at California State University, where Dr Andy Galpin, summarised the results: "All we test in our lab is elite level athletes. So what we found out today is not that Conor is elite. He is elite compared to the elites.
"He has exceptional balance. He's got amazing movement, he generates movement in the exact right places. He's incredibly fast and very powerful."
Athleticism was perhaps not enough to turn him into a superstar. Like Muhammad Ali, he is also a master of showmanship. Early on in his career he outlined his approach in an interview: "When you're in the fight business, you're constantly trying to promote yourself. If you talk the talk and walk the walk, it makes people interested in you. If they're interested in you, they'll pay to watch you, win or lose.
"So yeah, I'm cocky; I'm going to whoop everyone's ass. I'm going right to the top and there's no stopping me!"
His trash-talking persona has led him into trouble, and there have been accusations of racism. He was dubbed the "Donald Trump of sport" after he called on Floyd Mayweather to "dance for me, boy!" And he was accused of ridiculing the Islamic faith of his last opponent, Khabib Nurmagomedov.
Through all his victories and troubles, he has remained with his girlfriend Dee Devlin.
The couple met in 2008 well before he was famous, and they have two young children. They were recently reported to have bought a mansion at Castledillon in Kildare. It was once the home of Albert Reynold Jr, son of the late former Taoiseach.
On Instagram he has 31 million followers, as he promotes his clothing line and his whiskey, while posing next to fast cars like a Dublin 12 James Bond.
The alleged incident in the pub in Drimnagh will give more ammunition to his critics, but there is little sign that McGregor, the unemployed plumber who became a MMA multi-millionaire, has lost any of his swagger.
Birth of Conor McGregor at the National Maternity Hospital in Dublin.
As a slightly built 10-year-old boy, he joins Crumlin boxing club.
The family moved to Lucan in West Dublin. He meets new friends at Coláiste Cois Life, including Tomas 'The Tank' Egan, who interests him in Mixed Martial Arts.
Conor joins the Straight Blast Gym, which specialises in MMA and is quickly hooked on the sport.
He makes his professional debut with a knock-out win over Gary Morris and wins three of his next five fights. Meets his partner Dee Devlin.
McGregor excels in Cage Warriors, a European equivalent of the UFC, and after six consecutive knock-outs, claims the featherweight and then lightweight belts.
McGregor signs his first contract with the Ultimate Fighting Championship (UFC) and defeats Marcus Brimage in Stockholm.
He overcomes José Aldo for the UFC Featherweight Championship. He then defeats Eddie Alvarez to take the lightweight crown.
Pockets €80m for his heavily hyped fight with Floyd Mayweather, becoming the fourth highest-paid sports person in the world.
Pleads guilty to disorderly conduct at a UFC event in New York. Several people were hurt when he hurled a trolley at a bus. Later in the year there are riotous scenes after McGregor is beaten by Khabib Nurmagomedov.
In March, he announces his retirement for a second time.
In August, footage emerges of an incident in the Marble Arch Pub in Drimnagh, where McGregor appears to throw a punch at an older customer at the bar counter.